Calendar Reform87 min read

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What is leap year?
Leap Year?
published: grc 2018 Jul 12
version: 1.1

1. Table of Contents

Here is the table of contents for our rather lengthy discussion today:

  1. Table of Contents
  2. Introduction
  3. A Brief History of Our Current Calendar and Calendar Reform
    1. Calendar History in Brief
    2. Names of the Months
    3. Names of the Days of the Weeks
    4. Why the “Traditional Calendar” Starts on a Sunday?
    5. Links to Calendar Reform
    6. Conclusion
  4. Symptom Set I – Holiday and Scheduling Chaos
    1. Symptom – Shifting Holidays – Part I
    2. Symptom – Shifting Holidays – Part II
    3. Symptom – Event Planning for the Same Time Next Month
  5. Symptom Set II – Solar/Lunar Event Dating
    1. Equinoxes/Solstices
    2. Lunar Dating
    3. How About Easter?
  6. Symptom Set III – Personal and Businesses Finances
    1. Personal Finance
    2. Business Finance
    3. Trends and Analysis
  7. Calendar Issues Made Clear
    1. Uneven Length of Months
    2. Leap Day
    3. Conclusion
  8. Solution
    1. Introduction
    2. History of the 13 Month, 28 Day Calendar
    3. General Description
    4. Did You Know: 13 Week (Period) Accounting is Already A thing!?
    5. The Magic of the IFC in Action
    6. How to Implement the IFC?
    7. Benefits Overview
  9. Calendar Reform Tools
    1. IFC to Gregorian Calendars
    2. Programming and Scripting Tools
  10. Rebuttals of Disadvantages and Arguments Against the IFC
    1. Change is Hard!!
    2. Significant Dates May Change!
    3. My Birthday is on now a Wednesday! Noooo!
    4. Quarter Math is Hard!!
    5. Triskaidekaphobia!
    6. I will get charge more each year because of one more month!
    7. This Calendar Will Not Be So Useful When We Get Into Space, Right?
    8. Religious Objections
  11. Suggested Modifications – A Reformed IFC
    1. Start Calendar on a Monday
    2. Leap Day in February
    3. New Date Format
    4. Denoting Calendar Types
    5. Should we change the day or month names?
  12. Related Links
    1. Related Search Terms Via Google
    2. IFC Related Links
  13. Thanks for Reading

2. Introduction

In over a decade of me trying to figure out why our world is so messed up there have been quite a few ideas I have come up with or have discovered when thinking about how to make the world a simpler or better place, reform such as: time, metrics, language, culture, economy, and many others. However, here is one area of reform which you may have not ever considered, because it is such an integral part of our everyday life: Calendar Reform.

I had originally written about this topic for my micronational work (Republic of Talossa) in April of 2006, so this rewrite is a fairly significant expansion of my previous work, as well as being an attempt to put this idea before a much larger audience through my personal blog. My previous work was about 1,300 words and this one is approximately 13,000 words because, now, I am attempting to show you how and why and not just tell you, which I hope will be powerful!

Why do we need calendar reform you ask? Well, Hopefully, I can make that case here, so settle in for a ride that is going to ask you to think A LOT about our calendar, which we take for granted and give very little thought to about how we plan things and how it affects us in our daily lives.

Note: The data for the charts are found here in a Google Spreadsheet: Calendar Reform: IFC Data Spreadsheet.

3. A Brief History of Our Current Calendar and Calendar Reform

A. Calendar History in Brief

Julius Caesar ad Pope Gregory - Calendar Reform
Julius Caesar and Pope Gregory – Calendar Reform

Here is as quick summary of the history of our current calendar:

  1. Our calendar is a solar calendar which is based on Earth’s solar year.
  2. In case you did not know, our current calendar is called the Gregorian Calendar (Wikipedia) after Pope Gregory XIII who introduced it in October 1582.
  3. Prior to that we had the Julian Calendar (Wikipedia) (a twelve month calendar) after Julius Caesar instituted a reform of the Roman Calendar in 46 BC.
  4. Of course, that means that the Roman Calendar (Wikipedia) (a ten month calendar) came before that.
  5. Long before that they used lunar calendar of sorts which was adapted from Egypt.

Our current calendar is based on ideas from over two thousand years ago and its origin is heavily steeped in the early Roman Empire as well as the power of the Catholic Church within the Roman Empire.

B. Names of Months

The name of our months are all derived from the Greeks/Romans and their various attempts at calendar reform. [ A History of the Months and the Meanings of their Names ( ]

MonthName Origin
JanuaryNamed after Janus, The Roman god of gates and doorways
FebruaryNamed after the Roman Festival of Purification
MarchNamed after the Roman god of War Mars (Ares)
AprilNamed after the Greek god of Love and Beauty Venus (Aphrodite)
MayNamed after the Italic goddess of Spring Maia
JuneNamed after the Roman god of Marriage, Child Birth, and Well being Juno (Hera)
JulyNamed after Julius Caesar
AugustNamed after Augustus Caesar
SeptemberNamed as the seventh month
OctoberNamed as the eighth month
NovemberNamed as the ninth month
DecemberNamed as the tenth month

C. Names of the Days of Week

Greek Gods

The names of the days of the week originate from names of the classical planets from Greek Astrology which are also the named after Greek/Roman gods.

This color image which was found on Pinterest shows a collection of the major Greek Gods posed on the top of a mountain. The gods shown in order from left to right in roughly 2 tiers are as follows:

  • Tier 1
    • Demeter
    • Hermes
    • Zeus
    • Hera
    • Athena
    • Poseidon
    • Hades
    • Hestia
  • Tier 2
    • Apollon
    • Artemis
    • Hephaistos
    • Dionysos
    • Aphrodite
    • Ares

The table below has an x-axis (top) whose columns are Planet and Greek/Roman God and whose y-axis (left) has the days of the week. You can cross reference the days of the week with the table to find out which celestial object and which god(ess) to which the day is named after

DayPlanetGreek/Roman God

Read More:

D. Why the “Traditional Calendar” Starts on a Sunday?

Here is a good overall quote from an article from Gizmodo:

The first day of the week (for most), Sunday has been set aside as the “day of the sun” since ancient Egyptian times in honor of the sun-god, beginning with Ra. The Egyptians passed their idea of a 7-day week onto the Romans, who also started their week with the Sun’s day, dies solis. When translated into early German, the first day was called sunnon-dagaz, which made its way into Middle English as sone(n)day.

For some in the Christian tradition, the first day of the week is named in accordance with the creation tale in the first book of the Bible, Genesis, where one of the first things God did was say “let there be light, and there was light.”

Countries whose national calendar starts on Sunday (@ ChartsBin):

  • most of North America
  • most of South America
  • China, Japan and Phillipines
  • a few countries in Southern Africa

Although, not every country starts their calendar week with Sunday!

Read More:

There is a rich world-wide history of calendars and calendar reform from the Romans 10 month calendar in the BC’s and Napoleon’s attempts at a 10 month calendar in his metrification rage during the very end of the 1700’s, to the various lunar (12-13 month), as well as the Mayan’s and other 13 month calendars:

F. Conclusion

As you can see from above, our calendar and way of life is managed and defined significantly by the works of the formative Roman Empire and Christianity in our names, calendar, and reform. Will we ever be able to move beyond enslavement to the past and away from a calendar that actively stands in our way and slows us down, much like the QWERTY keyboard layout was meant to do, and to something more efficient, useful, and modern?

In short, this rather large document (13,0000 words+) will:

  1. … show you specific symptoms of the problems with our current calendar.
  2. … cut to the chase and make clear the specific traits with the Gregorian calendar that are causing these issues.
  3. … present to you the solution to help us all to solve the problem and to move beyond it.
  4. … give you some tools to see that it can be done, and links to help you learn more.

4. Symptom Set I – Holiday and Scheduling Chaos

A. Symptom – Shifting Holidays – Part 1

Why are the dates for these holidays stated as they are?

  • Thanksgiving: 4rth Thursday in November
  • Memorial Day: last Monday in May

What day of the month do those holidays fall each year?

  year date delta days
(4rth Thursday)
2018 Nov 22  —
2019 Nov 28  +6
2020 Nov 26  -2
Memorial Day
(last Monday)
2018 May 28  —
2019 May 27  -1
2020 May 25  -2

Here is a list of a few other holidays that are set like this to ensure they fall on the same day of the week in a given month:

  • Mother’s Day – 2nd Sunday in May
  • Father’s Day – 3rd Sunday in June
  • Labor Day – 1st Monday in September

Why do they set their holidays’ date like that and not just give a single date?

B. Symptom – Shifting Holidays – Part II

How about your birthday? Now, lets face it, my birthday should be declared a world-wide holiday! Am I right! =) I was born on Nov 16 in 1973, which was a Friday. Is it the same day of the week each year? Nope! Let us take a look:


day of weekdelta days
2018Friday (We got lucky here!)
2019Saturday +1
2020Monday +2
2021Tuesday +1
2022Wednesday +1
2023Thursday +1
2024Saturday +2

It… keeps… moving!!! Arrrgghhh!! How can I plan my party when my birthday keeps moving throughout the week! It looks like it is going to take us a few years to get back to a Friday birthday for a 3 day birthday weekend! However, I suppose I could use Monday as a 3 day weekend, but no one likes Mondays.  =( It is not until 2029 that my birthday falls on a Friday again – an 11 year wait! =O After that very long hiatus, I have to wait for the years 2035, 2040 and 2046 for a Friday birthday again. =(

How about some other holidays which are on a fixed day of the month? Let us see how they fall over the next few years:

  year day of week delta days
American Independence Day
(July 4)
2018 Wednesday  —
2019 Thursday  +1
2020 Saturday  +2
(October 31)
2018 Wednesday  —
2019 Thursday  +1
2020 Saturday  +2

… and so many other holidays and events. How the hell do we plan anything from year to year with the days of the week for a given date changing all… of… the… time!

C. Symptom – Event Planning for the Same Time Next Month?

Next, I want you to consider this situation: You are told to:

Negotiating Meeting Date/Time
Scheduling confusion!

Schedule the next meeting for the same time next month.

Well, today is August 31st and it is the the fifth Friday of the month too, sooo… =O

You will most likely be thinking at least one of few possible things. What exactly does this person mean by ‘the same time next month‘? Do they mean:

  1. the same day of the month next month (31st of next month)?
    Can’t do that because Sep has only 30 days in the month.
  2. so, last day of next month then?
    … which would be Sep 30 and a Sunday. So, would they want it on that Friday or the following Monday (business days only)?
  3. 30 days from now?
    … which would also be Sep 30 and a Sunday (see previous answer)
  4. the same day of the week in the same week of next month (fifth Friday of the next month)?
    Can’t do because there are only 4 Fridays next month.
  5. … so, the last Friday of the month, then?
    … which would be Sep 28 and a Friday which might work.
  6. four weeks from now (28 days)?
    (see previous answer)

You get different answers depending on how you interpret the request as I am pointing out above, albeit this is a bit of an extreme example. These sorts of questions increase cognitive load (requires thinking) and potentially creates confusion and some drama by potential miscommunication or faulty assumptions if someone is not forward or explicit enough about when they want that next meeting to fall. The fact that we have to think about it at all is problematic when we will all have to go through this process: having to consult the calendar for next month and the person or person(s) you are corresponding with to negotiate which date to use – which is a lot of lost thought and time, as well as unnecessary work for something that should be simple.

5. Symptom Set II – Solar/Lunar Event Dating

A. Equinoxes/Solstices

An equinox is where the Earth’s axis tilt creates a day and night of equal length, which occurs in the seasons which are transitional (spring and fall).

A solstice is where the Earth’s tilt creates either a really long day or really long night which occurs within the depths of the 2 most extreme seasons (summer and winter). [ The Seasons (Equinox and Solstices) Page ( ]

Equinox - Solstice
Solstice/Equiox Orbital Positions

Lets take a look at the calendar for equinoxes and solstices in Central Standard (Daylight) Time for the next bunch of years:

YearSpring EquinoxSummer SolsticeAutumnal EquinoxWinter Solstice
2018Mar 20Jun 21Sep 22Dec 21
2019Mar 20Jun 21Sep 23Dec 21
2020Mar 19Jun 21Sep 22Dec 21
2021Mar 20Jun 20Sep 22Dec 21
2022Mar 20Jun 21Sep 22Dec 21
2023Mar 20Jun 21Sep 23Dec 21
2024Mar 19Jun 20Sep 22Dec 21
2025Mar 20Jun 20Sep 22Dec 21

Each solstice and equinox must also be calculated each year due to the shifting nature of the calendar, although to be fair, it seems to be more sensitive to time. The first 3 seem to be more affected by date changes (+/- 1 day) every 3-4 years too. Of course, these will also fall on different days of the week too.

B. Lunar Dating

Lunar Phases
Lunar Phases

A full moon happens every 29.53 days with a lunar solar-year being about 354 days which is 11 days shorter than Earth’s solar year (of 365 days), therefore, depending on when the first full moon is, we end up with 12-13 full moons per year. If the first full moon occurs on the 11th of Jan or before then we will have 13 full moons. If it occurs on the 12th of January or later then we shall have 12 full moons. In 2018, as you will see below, we have 13 full moons and the first one, fortuitously for our example here, falls on Jan 1. [, Orbit of Moon (Wikipedia) ]

#datedelta daysname
1Jan 1 -2Wolf Moon
2Jan 31 +30Snow Moon
3Mar 1 -30Worm Moon
4Mar 31 +30Sap Moon
5Apr 29 -2Pink Moon
6May 29 0Flower Moon
7Jun 28 -1Strawberry Moon
8Jul 27 -1Buck Moon
9Aug 26 -1Sturgeon Moon
10Sep 24 -1Harvest Moon
11Oct 24 0Hunter’s Moon
12Nov 23 -1Beaver Moon
13Dec 22 -1Cold Moon
Full Moon 2018 - Gregorian Date Deltas
Gregorian Date Deltas for Full Moon Dates

As, you can see here, the days of the month that that the full moons fall on are wildly different from month to month (-30 to +30 days), for an event that is quite regular @ 29.53 days, which makes it difficult to predict or plan for this event.

C. How about Easter?

Date for Easter??
Date for Easter??

Easter in Western Christian traditions (Catholic and Protestant) is celebrated on the first Sunday following the first full moon after the Spring Equinox. As we show above, the date of the equinoxes shifts around a little bit based on changes every 3-4 years and the lunar calendar also moves around too due to its shorter solar year.

Although, as an interesting and useful side-note, Easter in Eastern Christian traditions (various Orthodox) still use the Julian Calendar to determine their dates. (Farmer’s Almanac)

As a note: For simplicity’s sake, the Catholic Church has set a fixed date for the equinox, March 21, though astronomically, the vernal equinox may also occur on the 20th. The paschal full Moon always falls on the 14th day of a lunar month; because ancient calculations (made in a.d. 325) did not take into account certain lunar motions, it may differ slightly from the actual full Moon date. Easter always falls on a Sunday between March 22 and April 25.

6. Symptom Set III – Personal and Business Finances

Let’s take a look a the adverse affects that Gregorian calendar has on personal and businesses finances:

A. Personal Finances

Let us take a look at our personal income. To keep our math simple for our examples we will make the following assumptions:

  • Jan 1 falls on a Sunday
  • get paid on Fridays (unless paid on specific days per month)
  • get paid $100 per full time work day
  • have 5 day work weeks
  • which makes for a base weekly pay $500 a week (we will not take taxes into account here for simplicity)
  • all holidays and sick time are fully paid

If you are paid:

pay periodicitynotes
monthlyWhy do you make less in February than any other month of the year?


  • January is $2,200
  • February is $1,900
  • March is $2,300
  • April is $2,300
on the 1st and 15thWhy does your check on the 1st of the month differ?


  • January is $1,200
  • February is $900
  • March is $1,300
  • April is $1,300

… and your check on the 15th of each month the same:

  • $1,000
on the 1st and 15thWhy do these day of the month fall of different days of the week?


Days of the week that Jan 1 falls on from year to year:

  • 2018 – Monday
  • 2019 – Tuesday
  • 2020 – Wednesday
  • 2021 – Friday (2 day bump)

Days of the week that the 1st and 15th fall on for our sample year:

  • January – Sundays
  • February  – Wednesdays
  • March – Wednesdays
  • April – Saturdays
  • May – Mondays
  • June – Thursdays
  • July – Saturdays
  • August  – Tuesdays
  • September – Fridays
  • October – Sundays
  • November – Wednesdays
  • December – Fridays
every 2 weeksWhat days of the month do your pay days fall on?


Assuming you get paid every 2 weeks on Fridays:

  • January
    1. Jan 6
    2. Jan 20
  • February
    1. Feb 3
    2. Feb 17
  • March
    1. Mar 3
    2. Mar 17
    3. Mar 31
  • April
    1. May 7
    2. May 21
every 2 weeksThen why is there a 3rd paycheck for 2 months of the year?


See above example.

every weekThen why are there mostly 4 paychecks per month, but in four months there are 5?


  • January
    1. Jan 6
    2. Jan 13
    3. Jan 20
    4. Jan 27
  • February
    1. Feb 3
    2. Feb 10
    3. Feb 17
    4. Feb 24
  • March
    1. Mar 3
    2. Mar 10
    3. Mar 17
    4. Mar 24
    5. Mar 31
  • April
    1. Apr 7
    2. Apr 14
    3. Apr 21
    4. Apr 28

These income irregularities can make it hard to plan to pay bills or to save money and can cause unintended bill paying and other financial mistakes.

B. Business Finances

As a note for this section, I am also a small business owner. We do not have employees as of yet, but this is something I do think about when I think of progressing our businesses.

Calculating Employee Paychecks

Let us pull from the above section and show that calculating pay for employees is erratic ($1900 – $2300 per month) which makes monthly financial planning difficult. Below, I pulled in the top 3 rows from the previous section for you to look at from the perspective of a business owner:

pay periodicitynotes
monthlyMonthly pay per person is different from month to month:


  • January is $2,200
  • February is $1,900
  • March is $2,300
  • April is $2,300
on the 1st and 15thIndividual paychecks on the 1st of the month:


  • January is $1,200
  • February is $900
  • March is $1,300
  • April is $1,300

… and paychecks on the 15th of each month will always be:

  • $1,000
on the 1st and 15thDays of the week that New Years Day (Jan 1) falls on from year to year:


  • 2018 – Monday
  • 2019 – Tuesday
  • 2020 – Wednesday
  • 2021 – Friday (2 day bump)

Days of the week that the 1st and 15th fall on for our sample year:

  • January –  Sundays
  • February  – Wednesdays
  • March – Wednesdays
  • April – Saturdays

With 5 employees the total of the monthly paychecks range from $9,500 – $11,500 per month which is a variance of $2,000 per month as a regular monthly expense, which can make it hard to plan finances month to month.

Production, Availability, and Uptime Planning

Each month there are different number of production, availability, or uptime hours for factories or other always-on industries such as hospitals, trains, subways, cabs, and large malls. Here we will assume 8 hour work days with 3 shifts a day and 7 days a week of operation:

Num Production Hours per Month - Gregorian
Num Production Hours per Month – Gregorian

… with the production time ranges from 672 to 744 hours per month which is quite a swing from month to month (102 hours difference) to plan and manage, and to look for trends in business. This compounds further difficulty when we add in the fact that many holidays fall on different days of the week or different days of the month from year to year which can make scheduling, planning, and predicting even more grueling in such demanding and always-on environments.

How many hours of uptime do I have to work with this month? OK, how about next month? The month after that? =O Which holidays fall here and on what days? Will that be the same next year? How do I perform a year to year analysis of uptime and productivity so I can plan for the coming year?

Bill Due Dates

When paying bills that fall on a given day each month (credit cards, cell phones, various services) they will fall on different days of the week each month and they will keep moving every year. So, as an example, pulling from the work above: Which days of the week do the 1st and 15th fall on for our sample year:

Day of Week for 1st of Month - Gregorian
Day of week for 1st of month. Sunday is 1; Saturday is 7
  • January –  Sundays
  • February  – Wednesdays
  • March – Wednesdays
  • April – Saturdays
  • May – Mondays
  • June – Thursdays
  • July – Saturdays
  • August  – Tuesdays
  • September – Fridays
  • October – Sundays
  • November – Wednesdays
  • December – Fridays

If you have a bill that is due on those days and their business only has 5 day billing support, then what do you do about billing questions of problems that occur with 1st of the month payments that fall on weekends, which happens for 4 of the 12 months this year? That will surely cause you annual problems not only for their business, but for your business and, also potentially your clients. Businesses also have to pay bills and so do regular people like you and I, in case you did not know that! There is nothing more frustrating than wanting to pay a bill and needing help and finding out that support is closed and the bill is due today. Now, let us ignore the procrastination issue here which is a post for another time. =)

Interest Rates and Returns

Calculating interest rates, bonds, interest accrued, principal payed, etc for savings, loans and mortgage payments, or dividends or stock returns is more difficult monthly and weekly differences and are often set to 30 days which can cause errors. I won’t go into this, because I am not too knowledgeable on it, but with all of the examples I have set forth I think you can see how this might be made more difficult due to our highly amorphous monthly calendar.

(If someone can provide examples or explanations, I would love to have it here!)

Personal and Business Finances – Together

Bills got ya crazy?!?!

Now, let us bring this all together so we can compound the problems with the moving target of when and how much we get paid throughout the month with a differing schedule of when bills are due, potentially differing total for bills, differing days of the week that bills are due on, or income is collected and see what this looks like:

Let’s say you are:

  • paid every 2 weeks
  • your first check is on Friday, Jan 6
  • you have 4 bills of note per month which are paid monthly on a specific date:
    • rent: paid by hand on the 1st;
    • student loans: paid through ACH on the 5th;
    • mortgage:  paid through ACH on the 15th;
    • cell phone: paid automatically through credit card on the 18th;

So, we have our bills and we have our pay schedule, lets see how they end up falling over the next few months and see how this works:

  Jan Feb Mar Apr May
Event DoM DoW DoM DoW DoM DoW DoM DoW DoM DoW
rent 1 Sun 1 Wed 1 Wed 1 Sun 1 Mon
paycheck   3 Fri 3 Fri        
student loan 5 Thu 5 Sun 5 Sun 5 Wed 5 Fri
paycheck 6 Fri         14 Fri 12 Fri
mortgage 15 Sun 15 Wed 15 Wed 15 Wed 15 Sat
paycheck     17 Fri 17  Fri        
cellphone 18 Wed 18 Sun 18 Sun 18 Tue 18 Thu
paycheck 20 Fri     31 Fri 28 Fri 26  Fri

Your paychecks are dancing all around your bills and all of your bills are falling on different days of the week, even on weekends! Over 5 months your bills fall on 4 different days of the week with the exception of Feb – Mar being basically and conveniently the same. Sometimes your checks arrive at the beginning of the month and sometimes they start to arrive towards the middle of the month, and sometimes there are 3 checks in a month! Did your checks fall such that you have the money in your account to pay your rent on time or do you have to pay within the grace period (by the 5th)? Wouldn’t that be stressful!

Due to the various days of the month continuously falling on different days of the week each year, as well as holidays, paychecks, and other significant events falling all over the months without any consistency, trends and analysis are much more difficult to process, predict, or follow especially with a given holiday sometimes falling as a 3 day weekend or even possibly during the middle of the week.

Is Christmas during the weekend or the middle of the week this year? How about Independence Day? How will that affect our sales, production needs, work load, or supply, demand, or delivery or production schedule? How does is it compare to last year?

Who the hell knows!

7. Calendar Issues Made Clear

Note: You may have noted that I tried to not spell these issues out explicitly to allow you to come to these conclusion yourself.  

It may be hard to believe that just 2 issues can cause so much calamity, but as we have shown above, the real calendar culprits which causes most of the problems are two things:

  • uneven length of months
  • Leap Days

A. Uneven Length of Months

Months to Knuckles method of determining how many days in each month.
Months to Knuckles method of determining how many days in each month.

The Gregorian Calendar is an annual calendar which means it needs to be updated each year. It has months with differing number of days and number of weeks, as well as having the days of the month fall on different days of the week each and every year. The following is a list of the number of days and weeks per month:

  • 28 days and 4 weeks: February
  • 30 days and 4+ weeks: April, June, September, November
  • 31 days and 4+ weeks: January, March, May, July, August, October, December

… which causes the days of the month to fall on different days of the week each year. There is no consistency which makes scheduling things or trying to trend analysis like trying to hit a continuously moving target!

To help remind you of this phenomenon here is which days of the week Jan 1 falls on for the next few years:

yearday of week for Jan 1

See our favorite little 2 day bump there for 2021? That brings us to the next section:

B. Leap Day

Now, you might be asking “Why are there 2 day bumps every 4 years for many of the holidays and other dates“?.

This is because each of Earth’s solar year is approximately 365.2422 days – about a quarter day (5.81 hours) longer than our calendar which does not do partial days. Because of the partial solar day per year we have to add an additional day into the calendar every 4 years (Leap Day on Feb 29) in order to compensate for that lost time otherwise, at some point, our seasons would occur in the opposite part of the year.

Leap Year
Leap Year Orbital Positions

The compounded effect of the loss of a quarter day every year would result in the the calendar slowly sliding backwards – year after year, quarter-day by quarter-day. After 224 years of losing a quarter-day we would be about 6 months behind, so Christmas would slide back in seasons to be found at the end of June, and so on with the rest of the calendar similarly slid. We would have to wait a total of 448 years for the calendar to be right again, which is a really long time to wait for white Christmas.

As an example, from the moment of the shift to the Gregorian Calendar in 1582, assuming we did not incorporate Leap days:

  • in 1806, near the beginning of the Victorian Era, after 224 years have passed, Christmas would have shifted be in the heat of summer.
  • in 2018, 436 years have passed, so the actual date of Christmas would fall 12 days earlier in the season, where Dec 13th is now.

This adding of an additional day to the calendar further shifts a calendar to fall on a different day of the week every 4 years, pushing our calendar further and further out of wack making scheduling and planning even more difficult. This also affects equinoxes and solstice dates which are set back by that quarter day each year and then are some are bumped a day due to the addition of Leap Day.

C. Conclusion

With the Gregorian Calendar being an annual calendar and having to be generated each year due to the days of the month falling on different days of the week… every… year, which is also compounded by the addition of Leap Day every 4 years so scheduling events or even attempting year to year trend analysis or predictions is very, very difficult.

But, we can do better…

8. The Solution

A. Introduction

The solution that I will introduce will solve the above 2 issues and all of its accompanying symptoms, as well as such benefits as:

  • create more standardized and consistent dates and events each year
  • make month to month and year to year planning and trend analysis easy
  • simplify our daily life by reducing cognitive load (thinking) as well as the accompanying work and drama when trying to plan and schedule things.
Calendar Yea!
Calendar Yea!

My solution is called the International Fixed Calendar (IFC). I introduced the International Fixed Calendar – a 13 month 28 day perpetual calendar – in a micronational post (Republic of Talossa) way back in April of 2006 (~1,400 words) and I have been a rabid fan of this solution since then.

Below, I will:

  1. go through a general history of 13 month, 28 day calendars
  2. take a look at the calendar itself
  3. show you the calendar in action so you can see it and believe it
  4. give you some tools to work with it
  5. list its significant advantages

B. History of the 13 Month, 28 Day Calendar

13 month calendars have been found all throughout history and all throughout the cultures of the world:

The 13-month, 28-day alternative has been in use on this planet for more than 6000 years. In prehistoric India and China, and throughout South America it was the standard time-keeping system. The Essenes, Egyptians, Polynesians, Maya, Inca, Lakota, and Cherokee used a 13-month, 28-day calendar. The Celtic knowledge of the Druids is based on the Tree Calendar, also a 13-month, 28-day calendar. Today many cultures are still using their traditional 13-month calendar system.

Throughout recent history others have proposed this sort of plan:

1745One of the earliest known modern presentations of a 13 month 28 calendar was introduced in 1745 by Hugh Jones, an American colonist from Maryland, as the Georgian Calendar in honor of King George II.
1849The French positivist August Comte in April 1849 created such a plan and referred to it as the Positivist Calendar.
1899Moses Cotsworth of England created a similar plan in 1899 when looking at methods to simplify recording railway statistics.
1920’sWhen calendar reform was all the rage in the early 1920’s, George Eastman of America’s Eastman-Kodak tried as well, promoting the Cotsworth Calendar.

Other historical calendars that included 13 months:

  • all lunar calendars had 13 months some of the times, 12 months in others which encompasses many indigenous cultures and religions world-wide.

Read More

C. General Description

Here are the traits of the International Fixed Calendar:


  • there are 13 months to a year
  • each month begins on a Sunday
  • each month is exactly 4 weeks (28 days) long
  • 13 months at 28 days each makes for 364 days a year.

OK, so above is the basic idea of what the calendar is, but let me show you the monthly calendar below to get your ideas flowing:

SundayMonday TuesdayWednesdayThursday FridaySaturday

Here is a cleaner printable version of the International Fixed Calendar in Google Docs.

This is the calendar for every… single… month.

This does not change. You will not need a new calendar each month or each year. Just this one.

Refreshing, huh!

New Stuff for the IFC:

13th Month

The extra month, which shall be named Sol, is inserted between June and July to minimize the date displacement and to keep the current month to season match. Plus, with Sol being Latin for sun and being placed within the depth of the heat of summer (at least here in the US), the name fits quite well. Plus, it is also the month in which the Summer Solstice happens.

Here are the months of the year (4 weeks @ 28 days) just so you can see them:

  1. January
  2. February 
  3. March
  4. April
  5. May
  6. June
  7. Sol
  8. July
  9. August
  10. September
  11. October
  12. November
  13. December

So, we have 13 months @ 28 days which makes 364 days, which brings us to the next part of our fancy new calendar:

Intercalary Days

Intercalary Days are days that exist which will not be present on the monthly calendar and do not cause day of week changes. Intercalary days are added:

  • … at the end of the year called Year Day that falls outside the Calendar which shall be considered, for purposes of dating, as December 29th and shall be the 365th day of the year.
  • .. during Leap Years called Leap Day that is added at the end of the June which, for dating purposes, shall be June 29th.

Here is how this will flow:

Year Day – has a date, which is definitely needed to record dates, right, but it will be considered a world-wide holiday and it will NOT be assigned a day of the week so that it will not cause a shift in the calendar.

  1. Saturday, Dec 28
  2. Year Day, Dec 29
  3. Sunday, Jan 1

Leap Day: A similar thing happens to Leap Day too which would also be considered a world-wide holiday:

  1. Saturday, Jun 28
  2. Leap Day, Jun 29
  3. Sunday, Sol 1

3-day holiday weekends anyone!!!

D. Did You Know: 13 Month (Period) Accounting is Already a Thing?!

In case you did not already know this, but, currently, many industries are using a 13 month (or 13 period) accounting method internally. Industries such as:

  • accounting/finance
  • broadcasting/media
  • manufacturing
  • publishing
  • restaurants
  • retail

They already see and are using the power of a 13 month year for analysis and prediction. Shifting to the IFC will help to make this practice even more relevant and powerful with days of the week being the same each month and holidays and other events falling on the same day each year.

E. The Magic of the IFC in Action

Here is a some full year calendars for you:

The Basic Conversion Process

As far as converting from the Gregorian Calendar to IFC, perhaps the easiest way (since the Gregorian Calendar shifts days of the week all of the time) would be to start with a year where the the day of the week for Jan 1 of the Gregorian Calendar matches the IFC day of the week (a Sunday), and then do the conversion match to the IFC calendar just to make sure there are no issues.

Now, an interesting side effect of this process is that some dates may change months in the new calendar, especially the dates that follow June due to the addition of that 13th month in the middle of summer. Now, keep in mind their new IFC dates and days of the week will never change from there.

Here is a calendar I put together for just that purpose: Gregorian to IFC Conversion Calendar.

Leap Day Birthday Conversions

Those who currently have Leap Day birthdays in the Gregorian Calendar will be intimately familiar with this issue because Leap Day, as a date out of time which only pops into the Calendar once every 4 years, means they already have to decide when to celebrate their birthday yearly. This is not going to change so much here.

The above conversion method does not have Leap Day in the list of Gregorian Calendar dates, however, doing the conversion with Leap Day in the calendar date sets the rest of the dates off for the rest of the year by a whole day, which would seem weird and is NOT a good idea.

The following conversion methods for birthdays and other events that fall on that day, which is something that those who currently have Leap Day birthdays will be intimately familiar with:

  1. Use the next Gregorian day (grc Mar 1) as your birthday and then convert to the IFC date (ifc Mar 4).
  2. Use the new IFC Leap Day as your birthday (ifc Jun 29). Hey, it is a birthday out of time which phases into existence once every 4 years, so why not have it phase into a completely different quarter!

For automated conversions we will use method 1.

Fixing‘ the Dates

So, let us take a look at the date setting symptoms from above from (the holidays and events) and see how those issues would be solved with this amazing 13 month and 28 day calendar. In both symptom cases with the new calendar, the holidays and other significant events could be fixed on a single date and they would always fall on the same day of the month and day of the week each month and each year.

  Gregorian IFC
holiday/event previous date previous day of week new date new day of week
New Years Day Jan 1 various Jan 1 Sunday
Spring Equinox Mar 20 – Mar 21 various Mar 20 Tuesday
Easter first sunday following the first full moon,
following the Spring Equinox
currently simplified to ~ Mar 22 – Mar 25
Sunday April 15 Sunday
Mother’s Day 2nd Sunday in May Monday May 22 Monday
Memorial Day last Monday in May Monday June 9 Monday
Father’s Day 3rd Sunday in June Sunday Sol 1 Sunday
Summer Solstice June 20 – 21 various Sol 4 Wednesday
Independence Day July 4 various Sol 17 Tuesday
Labor Day 1st Monday in September various Aug 23 Monday
Autumnal Equinox Sep 22 – 23 various Sept 13 Friday
Halloween Oct 31 various Oct 24 Tuesday
My Birthday Nov 16 various Nov 12 Thursday
Thanksgiving 4rth Thursday in November Thursday Nov 19 Thursday
Winter Solstice Dec 21 various Dec 19 Thursday
Christmas Dec 25 various Dec 23 Monday
New Years Eve Dec 31 various Dec 29 intercalary day

Another idea that has been suggested is that most holidays could be shifted to a Friday or a Monday so everyone gets a longer weekend in addition to a wonderful and more convenient calendar. Everybody wins!

Lunar Dating

Again, here we got really, really lucky with the first full moon of 2018 falling on Jan 1 which will provide a great example:

#grc Datedeltaifc Datedelta
1Jan 1-2Jan 10
2Jan 31+30Feb 3+2
3Mar 1-30Mar 5+2
4Mar 31+ 30Apr 7+2
5Apr 29-2May 8+1
6May 290Jun 9+1
7Jun. 28-1Sol 11+2
8Jul. 27-1Jul 12+1
9Aug 26-1Aug 14+2
10Sep 24-2Sep 15+1
11Oct 240Oct 17+2
12Nov 23-1Nov 19+2
13Dec 22-1Dec 20+1
Full Moon - Gregorian vs IFC Date Deltas
Blue line is Gregorian Deltas; Red line is IFC Deltas

Gregorian Delta: In the Gregorian calendar from month to month, the delta for the date of the full moon varies by as much as -30 days to +30 days, which is a very broad range; although the more normalized range (if we kindly ignore the +30’s at least for this year’s erratic calendar) falls between -2 and +1 – a more modest range date range of 4 (-2, -1, 0, 1).

IFC Delta: As we pointed out above, the lunar year is shorter than ours (354 days) and the lunar month is near the same (29.53 days), however with a consistent 28 day month we can better predict the changes of the date of the next full moon from month to month, which amounts to same date next month + 1 day or +2 days, so  this calendar is more in sync with lunar patterns.

Event Planning for the Same Time Next Month?

Let us take a look at our previous example of:

Day of Week for 1st of Month - Gregorian vs IFC
Blue is Gregorian; Red is IFC; Sun is 1 and Sat is (7)

Today is August 31st and it is the the fifth Friday of the month too, sooo… =O  Friday, August, 27th, the fourth Friday of the month and you are told to: “Schedule the next meeting for the same time next month.“.

You will most likely be thinking but ONE thing:

Ok, so same time next month which will be: Friday, September 27th. Got it. Done.

How oddly unpainful this was because of the 4 full weeks per month and the days of the month falling on the same days of the week each and every month. We can have a simpler and more efficient world!

Personal and Business Finances

Articles from calendar reform history the issues and how the IFC makes running a business easier:

Let us take a look at how much the International Fixed Calendar will greatly simplify our financial lives:

Again, to keep our math simple for our examples we keep the following assumptions from above:

  • Jan 1 falls on a Sunday
  • get paid on Fridays (unless paid on specific days per month)
  • get paid $100 per full time work day
  • have 5 day work weeks
  • which makes for a base weekly pay (before taxes which we will not take into account here) $500 a week
  • all holidays and sick time are fully paid

No matter how you are paid your checks are the same each week/ 2 weeks/ month:

  • weekly: $500
  • 2 weeks or 1st and 15th: $1,000
  • Monthly: $2,000

Paydays (Fridays) fall on the same day of the month each and every month and are as follows:

  • 6th
  • 13th
  • 20th
  • 27th

… and there are always 4 complete weeks each month and no partial weeks to mess things up.

13 Periods: There are 13 pay periods and 13 billing periods so money changes hands quicker and more evenly. These were present before, but were hidden behind the 12 month periods with some months having extra days/weeks per month and extra paydays in them.

Small Check Variability: The only variability here is December which will have 1 more day so the monthly total will be $2,100 which is easy enough to deal with. Now, in Leap Years, June will have 1 more day and the pay will be $2,100 too.

Business Finances

Employee Paychecks

As a business owner, no matter what periodicity you pay your employees with they are paid proportionately the same each period:

  • weekly: $500
  • 2 weeks or 1st and 15th: $1,000
  • Monthly: $2,000

…and paydays (Fridays) fall on the same day of the month each and every month, and those days are as follows:

  • 6th
  • 13th
  • 20th
  • 27th

… and there are always 4 complete weeks each month.

Again, the only variability will be in December (Year Day) and then June during Leap Years.

Calculating Employee Paychecks per Month: For 5 employees that is $10,000 per month, each and every month, except for Dec (and Jun in Leap years) which will be $10,500.

2018 Production Hours Per Month - Gregorian vs IFC
Blue line is Gregorian; Red line is IFC

Production, Availability, and Uptime Planning: The basic numbers per month are the same @ 672 hours per month. The only month that differs will be December with the one extra intercalary day at the end of the year (Year Day) (and then every 4 years in June for Leap Day which will have 696 as well).


Personal and Business Finances – Together

Now, let us bring this all together so you can see how much simpler and efficient your financial life will be for your personally and also for businesses too. We will keep the same assumptions from the previous sections.

  • paid every 2 weeks
  • your first check is on Friday, Jan 6
  • you have 4 bills of note per month which are paid monthly on a specific date:
    • rent: paid by hand on the 2nd (moved a day to not be on a weekend);
    • student loans: paid through ACH on the 5th;
    • mortgage:  paid through ACH on the 16th (moved a day to not be on a weekend);
    • cell phone: paid automatically through credit card on the 18th;

Here is your financial schedule for all the months:

  All Months
event DoM DoW
Rent 2 Monday
Student Loan 5 Thu
Paycheck 6 Fri
Mortgage 16 Monday
Cellphone 18 Wed
Paycheck 20 Fri

Your paychecks and bills happen at regular frequencies and happen at the same day of the week each month which makes it much easier to prepare, plan, and predict your finances.

Trends and Analysis

2018 Days Per Month - Gregorian vs IFC
Blue line is Gregorian; Red line is IFC

Trends and analysis become supremely easy here due to:

  • 13 months with the same length (4 weeks of 28 days)
  • days of the month falling on the same days of the week
  • holidays and other events fall on the exact same date each month, each and every year

Prediction and month to month and year to year comparisons become very easy with such regularity! What day of the week do American Independence Day or Christmas fall on this year or next year. The exact same days each year!

Some industries are already using 13 month periods for a more even comparison.

Other Benefits

More even quarters:

Days Per Quarter - Gregorian vs IFC
Blue line is Gregorian; Red line is IFC

Under our new IFC calendar overlord here our end dates for quarters all end on the same day of the week each and every year and the quarters are much, much more even, which is great for trend analysis and long term planning.

 end datedays in quarter
Q1Sun, Apr 791
Q2Sun, Jun 1491
Q3Sun, Aug 2191
Q4Sun, Dec 2892

Normally, only the 4th quarter has a different number of days (+1 day) due to the solar year having 365 days per year and not the evenly divisible 364 days. In Leap Years Q3 has 1 extra day due to the addition of Leap Day on June 29.

F. How to Implement the Calendar?

How could this be done once it is passed as the new world-wide calendar standard?:

  1. Post Date Effectiveness: Set the effective date for 10 years (or possibly to 2038 to solve the Y2038 issue – see below) in the future so everyone has time to get prepared and learn the new way. This will ensure that we have plenty of time to institute the needed things to make this happen and to ensure a smooth transition.
  2. World-wide: Governmental Cooperation:  All national governments and bodies will have to get involved to push this forward:
    1. sign treaties and pass this globally through the UN or other global body
    2. pass national laws, create calendar reform task forces, policies, and timelines for implementation
    3. decide on holiday and event date conversions
    4. create a technical businesses advisory platform
    5. ensure a public education program is put in place not only for citizens
  3. Programmatic Solutions: I will start this by saying that I am a programmer so I know a little bit about this. Computers store dates and time based on the number seconds from 1970 Jan 1 and that dates are not stored purely as standard dates. Dates are then calculated by counting the number of seconds and then converting that into a date: num seconds -> conversion formula -> date. I have had to work with this extensively myself, because I have already have written code in PHP and JavaScript which does the above conversion from our Gregorian Calendar to the IFC. Let me tell you, and other programmers will agree with me, Date math is a huuuuge pain in the ass.
    • Operating System (OS): To start, most of the far and reaching change could be handled by OS developers:
      • OS makers can create and implement the conversion
      • Send it out automatically in an OS update ahead of time as would be convenient and then it would be available as an additional OS calendar option. The sooner this was done the better.
      • Once the implementation date has come, the IFC Calendar would become the computer’s default calendar and date format.

      Every single Android, Windows, Apple, Linux device,etc would have it and most of the world would be updated simultaneously, kind of like they do with Daylight Saving Time. The conversion would just automagically happen. Most likely the OS owners will want to get this done as one of the first and earliest stages so that software developers can test and work with it to convert their applications.

    • Programming Languages: Much of this solution could be crowd-sourced, especially for open sourced software, and shared throughout the world so everyone would have access to a programmatic solution. One solution would probably be needed per programming language which could take shape as library of functions which could be implemented to do all of the conversion work, although much of this might have to wait until OS developers get their part done.
    • Independent Software: Other Software makers would have time to adjust their software to covert their software, hopefully using one of the open sourced solutions from above, or some may even just be able to pull from the OS updates.
    • Hardware: Hardware and electronic manufacturers would have time to adjust their hardware based models, do bios and firmware updates, etc… too. Some will need to create chip or other hardware update, or to created new model replacements to compensate and to drive us into the future, and to release us from the inefficient regressions of the past. Even if they cannot do this fully, date conversions are still a thing that can be done and the Gregorian Calendar can be used as a stop-gap until it is phased out!
    • Calendar Industry: Manufacturers of physical calendars would have plenty of time to adjust business models and to find other methods to monetize the new form of calendar, or to find new revenue streams. Perhaps they can start with educational programs to educate and help ease the transition for the populace and then upsell them to buy their calendar!
  4. Financial Industry: The financial industry will have some work to do to change to the new calendar:
    • Once it is implemented new loans, mortgages, investments, etc… will use the new calendar and will be more efficient, clear, and easier to work with.
    • Monthly bills will have to be recalculated for 13 months (12 month annual bill total/13).
    • Old loans, mortgages, investments, etc… can keep to the Gregorian calendar until they are completed, have been refinanced, or changed their terms which would then use the new calendar.
  5. Calendar goes into Effect: There will be a transition period where things will be wonky as people are adjusting, and the Gregorian and IFC dates will both need to be posted, but that time should pass quickly because OS, software, and firmware, etc updates will take care of most of the transition, and then we would never have to deal with that unsightly Gregorian mess of a thing again. Yea!

Smart Phone Revolution: Most people use smart phones and computers for date and time anyhow, so not much would change for most people, except for noticing the small changes to their calendar – some things are different: an extra month and some missing numbered days (29, 30, 31).

Y2K: We spent a shit load of time and money compensating for the Y2K issue which was the computer dates reaching the end of the 32 bit date storage. At least here when implementing the IFC, we will not be fixing something that may break things, but we will be making something that betters humanity, which will be money well spent.

Y2038 -Remember to turn off your computer before midnight on 1/18/2038!

Y2038 Guess what! In the year 2038 we will have another Y2K issue, the Y2038 issue where computers will have to figure out how to deal with dates reaching the end of their 64 bit dates. This date (Y2038) is a great date to aim for to implement the IFC – fix the date storage/conversion issue + implement a new calendar all at one time ushering in a new era!

G. Benefits Overview

The IFC simplifies the way that we think of the calendar and scheduling. Figuring out when to schedule things or what day of the week a scheduled event is becomes a very simple process. The main advantages to the IFC are:

  • Planning or scheduling events becomes easier because dates are consistent every month and every year with the days of the month falling on the same days of the week… all of the time.
  • You will always know what day of the week every holiday and day of the month is. No more guessing or confusion.
  • Finances are easier to maintain and plan due to equal month lengths. No more adjusting for unequal month lengths. No more wondering how many checks there are this month or where the payday falls. And 13 month accounting is already a thing and is being used in some industries.
  • There is faster money turn over due to their being 13 months instead to the year instead of 12 months.
  • Income and bills will be more regular – same number of days and weeks per month, paychecks will be the same regardless of how your get paid and you will get paid at the same time each month.
  • Same number of production hours each month
  • Trends are also easier to track due to equal month lengths and having holidays and other significant events fall on the same day of the week and month each and every year. There will be no guessing.

9. Calendar Reform Tools

I will post these at a later day because I have a considerable amount of recoding to do for a more general audience. I have code written for both JavaScript and PHP to handle the date conversions.

10. Rebuttals for Disadvantages and Arguments Against the IFC

Below are some arguments and complaints that have been used against the International Fixed Calendar along with my rebuttals and comments:

A. Change is Hard! Change is BAAAD!

Uggghh! This is a really lazy excuse! Next, are you going to yell at me to “Get off my lawn you filthy hippies!“?  All change is hard, but once it is done, life for all of us will be much, much better. Quit your whining and embrace a less complicated and more streamlined future! Think of the children!

Labor Movement
Labor Movement

Much like the changes brought to us by the world-wide labor movement, we took something bad and created something better. We adjusted to those changes too. Where previously we had such horrors as:

  • child labor
  • 20 hour works days
  • no sick time
  • no vacation
  • harmful working conditions

… after a long and bloody fight the labor movement demanded and received:

  • child labor laws
  • 8 hour work days
  • 5 day work week
  • vacation
  • sick time
  • workplace safety standards

We have all recovered and adjusted to those much needed changes well enough. =) Not too many people complaining about benefiting from those changes are there?!?

The world has also adjusted to the use of the world-wide imposition of such things as:

  • Time Zones
  • Daylight Savings
  • Y2K

People have also survived and adapted to the many purported signs of the beast through such means as:

  • social security numbers
  • savings account numbers
  • check numbers
  • credit card numbers

… so we can also adjust to a new calendar too! Just because you are used to the crappy and inefficient Gregorian Calendar (just like people were used to NOT having vacation time) doesn’t mean we should suffer eternally with it when there is a better option out there (require vacation) – The International Fixed Calendar.

B. Significant Dates May Change!

But, now American Independence Day (July 4) falls on Sol 17! What the hell is that!

Guess what, pony boy, every single country, religion, culture, and person, etc… in the world is going to have the same exact problem. It is not just you and your special snowflake holiday! Everyone is going to have to deal with changes to the dates of events that fall on a fixed date. Strangely, such things happen when you change calendars. It is part of the calendar reform process. Embrrrrace it!

There are 2 ways to deal with this

  1. Quit your whining, accept the new date, and welcome your new IFC Calendar overlord! Let the new holiday and event branding begin!! You can even add in an educational section on the previous date as well as calendar reform history!
  2. Use old date (July 4, etc), although you will have to figure out what you want to do for dates that fall on the 29, 30, or 31 of the month, because, thankfully, our new and snazzy IFC calendar does not have such archaic and inefficient things.

Once the new date is settled on, then it becomes just a change in advertising and branding.

Change, strangely, requires change, and we have to adapt in order to move forward, evolve, and truly progress humanity.

C. My Birthday is now on Wednesday!! NOOOOO!

See Above: If your birthday now falls on a non-optimal day of the week or even a different month entirely, then see the previous section for basic information on ways to deal with that.

Crying Meme!
Why God! Whyyyy!

Birthday’s on Holidays: Lets say, your birthday ended up on the same day as a holiday – which is already something that happens. Lets say my birthday now fell on Thanksgiving which is great for celebrating an annual comatose day, but not for celebrating me, so I feel your pain!!! You are not alone!

Everyone will have to adapt like they do currently if you have a holiday-birthday! You could celebrate with your half-birthday instead of your holiday-birthday. You could also join a support group those who are suffering with you! I know I will be doing so. Somebody hold me!!

Personal Agency: There is a good chance that your new IFC birthday will most likely change day and/or possibly even the month or even fall on a holiday now, so you could even utilize some personal agency with the new calendar change and say that your new IFC birthday is now on a Friday (or any other day you like). Everyone loves a Friday birthday! Embrace the calendar change and fix it for yourself too! No one will notice! I won’t tell! No one will judge you. This is a safe space!

Different Day: If your birthday ends up on and Wednesday (or other undesirable day of the week like on Thanksgiving or Christmas) then you can celebrate it on a different day, perhaps even on a Friday, much like people already have to decide on with our birthdays shifting days of the week each year.

Take the week off: You could even take your entire birthday week off like I do so you do not have to worry about something so petty and inconsequential as which date your birthday falls on because you will have the whole week to party and celebrate YOU!

D. Quarter Math is Hard!

Gregorian Calendar Quarters

The number months (and therefore quarter years) are not evenly divisible because 13 is odd and a prime number. Well, just because the month math was easy before did NOT mean they were really ‘even‘ to begin with, because the months per quarter did not have even days per quarter! The sad part here is that I actually had to pull out a calculator and refer to my list of days per month from above to figure this chart out! =(

  end date days in quarter
Q1 Fri, Mar 31 90
Q2 Fri, Jun 30 91
Q3 Sun, Sep 30 93
Q4 Sun, Dec 31 92

Let us also consider how radically different quarters really were from from quarter to quarter and year to year with the days of the week really shifting each and every month and each and every year. These shifting days makes quarters really a nebulous thing to begin with because holidays and events fall on different days per week which really sets payments, bills, data, and trends horribly, horribly askew.

Week-Based Quarters

Instead of calculating quarters directly by using the convenient and errant month-based math, we should do the math based off weeks, which is what many businesses are doing anyhow because of uneven weeks per month, i.e. each quarter is 13 weeks (oh crap – the number 13 again – run away) just like many are doing now, which is much simpler, and… Bam! problem solved.

Also, currently, many businesses are able to choose the dates for when their fiscal years begin and end too (How about Wednesday, Apr 3 for the beginning of OUR business’ fiscal year?)  so keeping to the not-so-useful and lazy month based math will really will not effect them, because they are already using the 13-week quarter math already. Honestly, there is really no real complaint here, beyond “Things are different! Ewww!

IFC Quarters

Days Per Quarter - Gregorian vs IFC
Blue line is Gregorian; Red line is IFC

Under our new IFC calendar overlord, here are the end dates for our basic 13 week quarters which end on the same day of the week each and every year.

 end datedays in quarter
Q1Sun, Apr 791
Q2Sun, Jun 1491
Q3Sun, Aug 2191
Q4Sun, Dec 2892

Only the 4th quarter has a different number of days due to the solar year having 365 days per year and not the evenly divisible 364 days that calendar gets us. So, there we add in the intercalary day Year Day. In Leap Years Q3 will have 92 days. The quarters end on the same day of the week each and every quarter, which is great for trend analysis.

E. Triskaidekaphobia!


It all started on the 13th hour of the 13th day of the 13th month.

Marge Simpson, Tree House of Horrors

Seriously! Triskaidekaphobia, the fear of the number 13, is going keep the world from moving forward? Irrationality, superstition, and fears are going to stop humanity… again… for the trillionth time in history… from making real progress and change! Surely we can evolve beyond such regressions.

Besides, Friday the 13 did not become and irrational superstition until the 1800’s and such a irrational fear is a fairly modern invention. (Origins of Friday the 13th as an unlucky day) Holy hell, I think the world is going to end because of a number! =O =(

Cool Number 13

A diagram of the number 13 as a Centered Square.
The number 13 as a Centered Square.

Strap on your math-geek hat, cause I am going to scream this from the rooftops: “13 is a cool number!“. 13 is a cool number because it:

  • … is composed of 2 prime numbers (1 and 3), and itself is a prime number! Isn’t that neat!
  • … is also a member of the Fibonacci Sequence (Wikipedia): 1, 2, 3, 5, 8, 13…
  • … is a centered square number
  • … is really 1+3 which is 4, so is 4 really that bad?
  • … and 13 x 13 is 169!

Just to freak everyone out completely, let us count up the 13’s in this calendar:

  • 1 – 13 months
  • 4 – 13-week quarters
  • 13 – Friday the 13ths … which is extra, superbad.

… that is 18 sets of 13’s (1+3 = 4) which makes 72.
18 and 72 are not so scary are they? See, it is not so bad! =O

Keep Calm and Love Number 13
Keep Calm and Love Number 13

13 is also a cool number because:

  • … the US had 13 colonies as well as 13 stars and 13 stripes, surely, assuming you are American, that this is a great and positive number for it signifies the very beginning of the United States of America.
  • … in case you were not aware, the movie ‘Friday the 13th‘ was not a documentary. =O
  • … ~36% of the years there are 13 full moons in a year.
  • … there are 13 4-week pay periods in a year. Give me mo’ money!
  • … 13 month accounting is already a thing;
  • … in Italy and China 13 is a lucky number!
  • … a Baker’s Dozen is 13 too!
  • … a standard deck of cards has 4 suits of 13 cards.
  • … at 13 years old you can watch PG-13 movies!!
  • … in Judaism at 13 years old you become a Bar Mitzva

If we want to evolve beyond the fear of the number 13 then we really just need to embrace it and its coolness as well as the number 4 and 72. Sooo much goodness with the number 13!

The Sacred Number 13

Let us take a slightly more serious venture into the world’s theological history. There was a time when not only was 13 was a very sacred number, but so was Friday (which was named after Aphrodite/Venus and is also associated with the older Nordic goddess Freya) the 13th. Both were considered a sacred within many divine feminine traditions, including the Christian divine feminine traditions which revolve around Mary Magdalene.

Some academics postulate that the number 13 and Friday the 13th were made to be pejorative because of the rise and dominance of patriarchy in the world’s traditions and cultures, especially within Christianity, which needed to cast women down as well as their sacred and empowering divine religious traditions.

Perhaps, we need to reclaim this once sacred number and this sacred day (Friday the 13th) and this sacred number (13) so we can honor women and their divine feminine traditions, bring on world peace, as well as bring on the IFC!!

F. I will get charged more per year because of 1 more month!

Monthly bills will need to be recalculated to 13 months by adding together how much you would be charged in one 12-month year and then divide by 13 and Wham! there is your new monthly bill.

Example: If you were charged $100 per month for a bill, then that would result in an annual total of $1,200 per year. Divide that by 13 and you get about $92.31 which could be rounded up or down depending. Keep in mind, your bill will end up with the same yearly total and you are still getting paid the same amount each year too.

G. This Calendar Will Not Be So Useful When We Get Into Space, Right?

Ok, so the short answer is: “Yes it will.”  =)

Humanity’s Planet of Origin: Earth

Humanity’s internal clock has evolved in harmony with the Earth’s solar calendar – 24 hour solar day, 365.2422 solar year, seasons, and all of that. Daily, our circadian rhythm hums in harmony with it and it will for a very, very long time because evolution takes thousands and thousands of years to effectuate evolutionary change.

Even if we travel to other planets we will still need a method of recording time that will be standardized and understandable throughout humanity no matter where we are in the universe, so keeping time with reference to our planet of origin, or more specifically to where our internal circadian cycles are synced to, will still be useful as a way of recording how time passes.

How long have we have lived on Mars?”

“12 Earth Standard Years (ESY), I think.

How About Unique Planetary Solar Years and Solar Days?

Each solar system, planet, and moon will still have its own solar year and solar day too, but those will not be useful for general record keeping for humanity. It will only really be useful when you are specifically talking about that planet and its cycles and it will most likely be measured with respect to Earth’s solar year and solar day since that is a scale that we are intimately familiar with Earth Standard Day (24 hours) and Earth Standard Year (365.2422 ESDs).

Here is a sample of our planetary solar years and solar days to give you an idea:

planetsolar daysolar year
Mercury175.95 ESDs0.24 ESYs
Venus224.7 ESDs0.32 ESYs
Earth1 ESD1 ESYs
Mars1.03 ESDs1.18 ESYs
Jupiter0.41 ESD11.86 ESYs
Saturn0.44 ESD29.5 ESYs
Uraus0.72 ESD84 ESYs
Neptune0.67 ESD164.8 ESYs
Pluto6.4 ESDs248 ESYs

Notes: Stats from Universe Today., Pluto Days, Pluto Years

I am pretty sure I cannot stay up for even 1/10 of Venus’ solar day which is a whopping 224 ESDs long which is about the length of a normal Monday, right!?! Using Venus’ solar day and night for personal time keeping is not going to be so useful, so we will still be using a 24 hour clock and ESDs because of humanity’s circadian rhythm will demand it. If we still use a 24 hour day, then we will still need a calendar that is based on that.

Human Interstellar Travel, Time Dilation, and Evolution

Here, we are getting into something far beyond consideration for this article and are traveling into the realm of what would currently be considered science fiction. By the point that we have to really ask this question a new time and calendar concerns will be dealt with, by something that is hopefully far superior to anything we can imagine up today.

H. Religious Objections

If this is soooo kewl, then why did it not get adopted by the world?!?!

Its adoption was primarily opposed and stymied by fundamentalist Christian sects (and the eventual rise of WWI). It was the vehement protests of Sabbatarians and Seven Day Adventists (and other similar Christian sects) who slavishly adhere to the 7 day week as set forth in the Bible that mostly kept the IFC from becoming a reality. The intercalary days (Year Day and Leap Day) do not affect the progression of the calendar’s days of the week and, therefore, disturbs the contiguous progression of the calendar’s 7 day week.

Biblical Responses: A possible Biblical retort to this problem maybe a Biblical quote or two:

  • from Mark 2:27 The Sabbath was made for man and not Man for Sabbath. in other words the Sabbath was made for humanity and that man was NOT made for the Sabbath and should NOT be be a slave to it
  • from Matthew 12:11-12(11) And he said unto them, What man shall there be among you, that shall have one sheep, and if it fall into a pit on the sabbath day, will he not lay hold on it, and lift it out? (12) How much then is a man better than a sheep? Wherefore it is lawful to do well on the sabbath days..

There are also a few mentions of an 8th day or an 8th week, that I have to look into, which I found interesting and possibly relevant. Here is a search for “8th day” OR “8th week” bible to get you started if your are interested.

Also, as as note, here is a link talking about this: Metonic Cycle and the 13th Month. I do not know much about this. Others will have to research the veracity and usefulness of these claims.

Weekly Religious Services: Religious services happen all throughout the week for the various religions of the world so a day outside of the calendar will not really change this, such things will continue to be a thing. If they need to take a day off and make a request for religious exceptions to work schedules then they can do that. Perhaps, as a part of enacting the IFC, it should be known that members of these sects may require religious exceptions to their work schedule for their religious calendar. Various religions of the world have to do that anyway for their holidays which have not been already secularized or adopted as a national or local holidays. Why should they be any different?

Another Day of Worship: The intercalary days (Year Day and Leap Day) could be seen within their sects as another day of rest and of worship – more of both which is good for everyone! (Perhaps an extension of the Sabbath since it was made for us?)

Concurrent Religious Calendars: Perhaps, the most powerful response to this issue is that, currently, many religions and cultures use their own calendars concurrently with the prevailing world-wide secular calendar.

There are so many more other calendars throughout the world that are used concurrently with the world-wide secular calendar so, not so much will really change for them. The rest of the world’s religions, even the Sabbatarians and the Adventists, can follow suit and use their own religious calendar concurrently with the new world-wide IFC calendar.

Why should the rest of the world be held hostage and held back from progress and evolution because of an unaccommodating religion which thinks it is more special than the other religions and cultures world-wide which are using their own calendar in parallel with the world-wide secular calendar. Religion is personal issue and is a private choice and the rest of the world should not be held hostage by them when there is a solution – concurrent calendars.

11. Suggested Modifications – a Reformed IFC

Yes, I am suggesting a few reforms to my proposed calendar reform idea! =) What I have proposed above is the basic International Fixed Calendar. Calendar Reform: the gift that keeps on giving! =)

I posted the pertinent parts of this to a new post titled Reformed International Fixed Calendar (rIFC).

A. Start Calendar on a Monday

To help with the Friday the 13th issue we can start the calendar on Monday instead of Sunday which:

  • gets rid of Friday the 13th
  • allows each year, month, and week to start on a Monday which makes more sense since Monday is the beginning of the work week and has the full weekend at the end of the week
  • the intercalary days will be found at the complete end of the week and month so it can be the 29th day of the month and still part of the weekend.

Here is a calendar I put together for just that purpose: Gregorian to rIFC Conversion Calendar.

My google calendar is already setup with Mondays as the first day of the week, so I am already there. Here is a quick tutorial on how to do that. Below is the new monthly calendar set to Mondays as the first day of the month:

MondayTuesdayWednesdayThursday FridaySaturday Sunday

Here is a printable version of my Reformed International Fixed Calendar on Google Docs.

Now, I do kind of get why they had the intercalary days, which will also be holidays, fall in the middle of the weekend – it just seems to fit better in the middle of the weekend instead of at the end of it – verses of right before that thing called Monday.

Currently, here are the countries whose national calendar already starts on a Monday (@ ChartsBin):

  • most of Europe including Russia
  • India and Indonesia
  • Australia and New Zealand
  • a few countries in South America

B. Leap Day in February

Let’s keep Leap Day at the End of February like it is now. There is no real gain by changing it to June (except for a level of symmetry between the intercalary days). Also, this will allow those born on Leap Day to try to keep this day as their birthday if they choose to utilize some personal agency when adapting their birthday to the calendar change.

C. New Dating Format

As a part of this process, we should also shift to a more efficient and logical world-wide dating standard: year month day such as:

  • 2018 Jun 22
  • 2018 06 22

This will also help to set apart the new date from the old date by virtue of the format change too.

There is already an international standard ISO standard (8601) for this and some countries are already using this standard.

This format already works well for organizing computer directories and files. I use it.

D. Human Era Calendar

We should adopt a new beginning of human history called the Human Era or the Holocene Calendar. This suggests that we start the calendar history for humanity not by paying homage to one religion/culture started 2,000 years but a more important historical event which marks the beginning of what scientists call the Holocene Era – the rise of modern humans – by the finding of the first building made by humanity which was some 12,000 years ago.

Here is my article on the Holocene Calendar which includes a video.

E. Denoting Calendar Types

If it is needed to show which calendar is being used then use:

  • ifc before the date to denote a International Fixed Calendar date
  • rifc before the date to denote a Reformed International Fixed Calendar date
  • grc before the date to denote a Gregorian Calendar date

… such as:

  • ifc 2018 1 Apr
  • rifc 2018 1 Apr
  • grc 2018 1 Apr

F. Should we change the Month or Day Names?

Doing so results in no real immediate advantage nor corrects any significant issues, so I would advise against it, since that would be change for the sake of making change, and not because there is any real tangible benefit. Although, that being said, doing so would make it quite obvious that we are using the completely different calendar which may help to avoid confusion. It may also make the calendar a little easier to use as well set us free from the names of the months and  the days of week paying homage to a specific religion or culture which would make it more general to all of humanity.

Change of Month Names: If we did change the month names then we could return to Latin based names which translate to something like “one-month”, “two-month”, “three-month”, etc. As stated at the beginning of this document, the later months in the year of our current calendar follow this from when the Roman Empire had a 10 month calendar using Latin roots to name the months. These are those months that follow that pattern:

  • Sept-ember (7 month)
  • Oct-ober  (8 month)
  • Nov-ember  (9 month)
  • Dec-ember  (10 month)

We could add the names for the extra months like this:

  • Uniember (1 month)
  • Duember (2 month)
  • Triember (3 month)
  • Tetrember (4 month)
  • Quintember (5 month)
  • Hexember (6 month)
  • September (7 month)
  • October  (8 month)
  • November  (9 month)
  • December  (10 month)
  • ?? Deciuniember ?? (11 month)
  • ?? Deciduoember ?? (12 month)
  • ?? Decitriember ?? (13 month)

Someone smarter than I would have to correct this, but this is just a quick example of what we could try. In my opinion perfect Latin would not necessarily be needed because we would be aiming for usability and not technical grammatical correctness, although I am sure some would take issue with a less grammatically correct approach. =)

Esperanto’s number prefixes, albeit modified a little, have a Latin feel to them:

  • Unuember(1 month)
  • Duember (2 month)
  • Triember (3 month)
  • Kvarember (4 month)
  • Kvinember (5 month)
  • Sesember (6 month)
  • Sepatember (7 month)
  • Oktember (8 month)
  • Nautember  (9 month)
  • Dekember  (10 month)
  • Dekunuember (11 month)
  • Dekduember (12 month)
  • Dektriember (13 month)

Or how about this alphanumeric possibility:

  • 1month
  • 2month
  • 3month
  • 4month
  • 5month
  • 6month
  • 7month
  • 8month
  • 9month
  • 10month
  • 11month
  • 12month
  • 13month

… although this approach would potentially create an issue where you want to say something like “in 1 month from now” and not mean “in 1month“.

Change Day Names: Here is a sample of what the day names might look like using similar Latin roots:

  • Uniday (1 day)
  • Duoday (2 day)
  • Triday (3 day)
  • Quadday (4 day)
  • Pentday (5 day)
  • Hexday (6 day)
  • Septday (7 day)

The French did something like this following the revolution during their metrification craze.

… or another alphanumeric answer:

  • 1day
  • 2day
  • 3day
  • 4day
  • 5day
  • 6day
  • 7day

Again, we have similar issues with this alphanumeric approach.

13. Thanks for Reading

Can I get a “Well played, sir! Well played!” See what I did here in this document? Look really closely…

13 sections? 13,000 words? 13 month calendar with 13 week quarters and 13 Friday the 13ths! Holla!

I hope that if you noticed that there were 13 major sections in the Table of Contents that it did not set you wrong from the start, did it? =O =) See, there were 13 parts to this document. Not so bad, right? Nothing to be afraid of here! Keep calm and love the number 13 and our new IFC Overlord!

For those of you who made it this far, to the end of this rather large post, I thank you!

If you think that this is a good idea, then please share it with your friends and family, and random strangers on the street, through flyers, email, Facebook, Twitter, etc so we can let the world know about this great invention and to push for a change to a better calendar and a better life for all – the International Fixed Calendar!

Before we go I will leave you with some love from the Shire (which uses the Shire Calendar which is a 12 month 30 day calendar with 5 days added at the end of the year) to send you off to a new way of thinking of how to make the world a better place:

Its Over Its finally over
Frodo Baggins: “Its Over. Its finally over!”

8 thoughts on “Calendar Reform87 min read

  1. I would like to comment on modifications…. Starting on a Monday? Instead of starting on a Sunday, It may be simpler for people to adopt if the Day of the Week the year started on matched the current Gregorian calendar. Sure, it might not make weeks start on a monday, but the number of each day of the week will be the same each month, and will be simpler for each year. It would also give some variety to the calendar that some gripe about the IFC .

    The SOL calendar by Jim Eikner of Austin, Texas uses this difference. In fact, I think that is the only difference ???

    1. **** Day of Week to Start Calendar ****
      Because the Gregorian calendar is NOT a perpetual calendar, the first day of the year ALWAYS falls on a different day of the week, which creates an incredible amount of problems as I detail in this post:

      Days of the week that Jan 1 falls on from year to year:

      2018 – Monday
      2019 – Tuesday
      2020 – Wednesday
      2021 – Friday (2 day bump)

      And, of course, this ‘variety’ is a large part of our calendar’s problem.

      Honestly, with that modification we are really just looking at how the calendar is presented. Instead of the calendar being laid out like it is now with a rotating annual calendar days:

      Sun Mon Tue Wed Thu Fri Sat

      … we just shift it to:

      Mon Tue Wed Thu Fri Sat Sun

      …under a more wonderful perpetual calendar.

      This change also fixes other issues too as I mention in that section.

      **** Variety is the Entire Issue ****

      The ‘variety’ in Gregorian Calendar is the problem which the IFC is trying to fix. This whole post is about showing the many, many problems with the ‘variety’ in the Gregorian Calendar and how to fix it.

      **** Sol Calendar ****

      Yea, the Sol Calendar is the IFC calendar minus the intercalary days and moving the Leap Day, which essentially makes the calendar bordering on useless, because the variety is still there and it is no longer a perpetual calendar. I mean, it is still better than the Gregorian calendar, by a little bit, but it is still has many of the significant problems as I point out in this post, so it is not really worthy of use when we have the IFC or my rIFC.

  2. This is the modified international fixed calendar of 13 months with 28 days.
    Existing international fixed calendar (Cotsworth Plan) has some advantages and disadvantages. This calendar has 13 months of 28 days. Actual calendar (Solar) consists 365 or 366 days. In international fixed calendar, additional 1 or two days are kept non weekday blank days. But practically it is not possible.
    We modify the international fixed calendar by adding remaining days. This is called NIF Calendar. This calendar consists 365 days / 366 days which is same as current civil calendar.
    Current civil calendar has the following disadvantages.
    Total days per month is not uniform. (7 months of 31 days, 4 months of 30 days, 1 month 28 days in normal and 30 days in leap). So we need separate calendar for all 12 months.
    Finding the weekday of the day is difficult. Some algorithm is needed.
    Calendar Structure:
    First we divide the year (365.2425 days) into 13 divisions. (365.2425/13=28.095577). But in Gregorian structure (365.2425/12 = 30.436875. Normal year has 365 days and Leap year has 366 days.
    Total Year = 365 (or) 366 Days
    Total Year = 364 Days + 1 (or) 2 Days
    = (28 days x 13 months) + 1 (or) 2 Days

    We have 13 months with one leap month. Normal months have 28 days (absolutely 4 weeks – Quadweeks) and Leap month have 29 days in normal and 30 days in Leap year. First Model has the following structure.

    1. Arivumani,

      Thanks for stopping by! =)
      I think the rest of your comment was cut off. I am not sure.

      There is nothing not possible about the IFC. It is very usable. In fact it is more usable than any plan which uses Leap Weeks or Leap Months which are incredibly problematic and make life, planning, and trend analysis much more difficult.

      Here is my post on why Leap Weeks or Leap Months are a problem and are inferior to Leap Weeks:

  3. Hi James. Great work here on the Fixed Calendar. Interestingly, I’ve come to very similar conclusions and done similar work, which you can see here When two people come to similar conclusions independently like this, it usually means they are compelling.
    Others here might be interested in the simple conversion table I created and the, if I say so myself, succinct reasons for anyone doing business to adopt the Fixed Calendar. I’ve been using for my sole trading for years.
    Keep up the good work, James. I see we’ve both been inspired by the RBE concept, too.

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