Calendar Wiki

This proposed calendar is a solar calendar based around the equinoxes and solstices, and takes into consideration that the number of days in each solar quarter are different due to the earth's off-center orbit around the sun. This calendar continues the precedent of 12 months and 365 or 366 days per calendar year as set by the Gregorian and other calendars.

Measuring the solar quarters as the time between equinox and solstice, the author of the calendar observed that the earth spends more time in the spring and summer quarters than in the winter and autumn quarters. In the northern hemisphere each of the solar quarters are measured as follows:

  • The spring quarter is a little less than 93 days. (Spring Equinox to Summer Solstice)
  • The summer quarter is a little less than 94 days. (Summer Solstice to Autumn Equinox)
  • The fall quarter is a little less than 90 days. (Fall Equinox to Winter Solstice)
  • The winter quarter is a little less than 89 days. (Winter Solstice to Spring Equinox)

93 (Spring) + 94 (Summer) + 90 (Autumn) + 89 (Winter) = 366 days = one leap year. 366 days is fine for leap years, but 1 day must be subtracted on standard years. In the following table the author has divided each of these solar quarters by 3 and assigned the days to months:

Quarter Month Number of Days Equinox/Solstice Actual length (approx.) Combined length
Spring March 93 31 March 21 or 22 92.75 days 186.4 days
April 31
May 31
Summer June 93 (94) 31 June 21 93.65 days
July 31 (32)
August 31
Autumn September 90 30 September 21 or 22 89.85 days 178.84 days
October 30
November 30
Winter December 89 30 December 21 or 22 88.99 days
January 29
February 30
Total 365 (366) 365.24 days (one complete tropical year)

Leap Years[]

  • the author has given each month a length that best aproximates how long the earth spends in that section of the tropical zodiac. July receives 32 days on leap years because the time the earth spends in that section of the tropical zodiac is almost 32 days.
  • Just like the Gregorian calendar, leap years are 366 days.
  • Unlike the Gregorian calendar, leap years are computed based on the summer solstice. If the summer solstice would otherwise fall on the 22st of June (GMT) then a year leap year would occur the year beforehand to prevent that from happening. That effectively brings the summer solstice back to the 21 on the following year. That means that leap years happen every 4 or 5 years.
  • If this calendar were to be put into use, it would need to begin on or after a leap year that is observed with out a leap day. That is because a day must be omitted from this calendar before it can go into effect.

Standard Years[]

The author has chosen July as the month to shorten by 1 day on standard years for three reasons:

  1. Summer quarter is actually about 93.65 days long which is not quite 94 days. Since the actual lengths of the other solar quarters are closer to their rounded numbers, summer quarter is the best choice for subtracting a day on standard years.
  2. July is the longest month and the only month with 32 days, so it can handle giving up a day.
  3. We are already familiar with July as a month with only 31 days.

Phasing in 5-Day Weeks[]

Some people think that the year should be shortened to 364 days so that it is evenly divisible by 7-the length of the week. But since the length of the week is whatever we make it, why not make the week 5 days long instead. Then the 365-day solar year would divide evenly into 73 weeks. And months would divide into 6 weeks.

Of course this would only work if there were no objections of changing the 7-day week to a 5-day week. But that is not going to happen unless the 5-day week is phased in slowly. People must be allowed to continue to observe 7-day weeks for an indefinite grace period while getting used to the idea. For religious reasons people should always be able to observe the 7-day Sabbath.

But maybe one day in the future if people would have everything they need, they wouldn't need to work more than 2 or 3 days a week, giving them the familiar 2 or 3 days off on the weekend. And then the 5-day week would be embraced.

If a 5-day week were to be established, the author of the calendar suggests the new days of the week be given new names unlike any of the current days of the week so as not to confuse them, and so that both 5- and 7-day weeks could be observed simultaneously.

If 5-day weeks were to be established, the author of the calendar would not use intercalary days. Ultimately he thinks it would be desirable to make leap day an intercalary day, but he would leave that as an option for future calendar reform.

Benefits of this calendar[]

  • Quarter lengths more accurately match the actual lengths of each solar quarter by putting the longer months in the spring and summer months where the earth spends most of its time. This also illuminates the fact that earth's off-center orbit literally adds a few days to the spring and summer months.
  • On standard years, the 31-days months are consecutive making them easier to remember. The 30-day months are also consecutive.
  • All of the months have familiar 30- or 31-day lengths, except for January which is a 29-day month, and July which has 32 days on leap years.
  • Leap years are computed based on the summer solstice always happening on June 21 which means that unlike the Gregorian calendar it is not possible to be in error.
  • The Gregorian calendar can go for as many as 8 years without having a leap year. But this calendar never goes more than 5 years without having a leap year. This is more accurate since an extra day must always be account for after 4 or 5 standard years. (This is because every standard year .24219878 days are not accounted for.)
  • There are 6 consecutive months in this calendar that match closely to an average lunar month of 29.53 days. The Gregorian calendar only has 4 on a standard year and they are never consecutive.
  • The longer months happen intuitively during the time of year when the days are also longer for the northern hemisphere.
  • The months of this calendar more closely match the time the earth spends in each section of the tropical zodiac.
  • December 25 is the same day on the Gregorian calendar as it is on this calendar.
  • With 5-day weeks, this calendar could easily be turned into a perpetual calendar with only one intercalary day per leap year. That beats most other perpetual calendars that usually have at least 1 intercalary day per year if not more.
  • The equinoxes and solstices always happen at the same time of the month and so are easier to remember. If the new calendar were to be implemented on January 1 of 2010, then here is when the equinoxes and solstices would occur (times are GMT):
Year Equinox Mar Solstice Jun Equinox Sep Solstice Dec
day time day time day time day time
2010 21 17:32 21 11:28 22 03:09 21 23:38
2011 21 23:21 21 17:16 22 09:04 22 05:30
2012 22 05:14 21 23:09 21 14:49 21 11:12
2013 21 11:02 21 05:04 21 20:44 21 17:11
2014 21 16:57 21 10:51 22 02:29 21 23:03
2015 21 22:45 21 16:38 22 08:20 22 04:48
2016 22 04:30 21 22:34 21 14:21 21 10:44
2017 21 10:28 21 04:24 21 20:02 21 16:28


  • A 32-day month is not desirable because it would be better to have all months be familiar lengths of 30 or 31 days. Alternatively you could make January 30 days long and make February the leap month (as we are already familiar) giving February 29 days on standard years and 30 on leap years. But then the vernal equinox and the summer solstice would come a day earlier in the month than expected on leap years.
  • A 29-day month is not desirable, because it would be better if all of the months were about the same length. To accomplish that, you could make January a day longer and March a day shorter giving them both 30 days, then all the months would always either be 30 or 31 days long. But then the vernal equinox would come a day earlier in the month than the other equinox and solstices, and that would sort of defeat the purpose of this calendar. But maybe that wouldn't be too big a sacrifice. If you moved leap day to March, the summer solstice would also come a day earlier in the month on leap years.
  • This calendar does not propose any major benefit that would necessarily be worth the undertaking of changing the current calendar system worldwide. Nor does it solve any of the problems with the Gregorian calendar that have lead to other attempts at calendar reform.
  • Holidays like Halloween and New Years Eve would have to be changed to the 30th, because October and December would each lose their 31st day. January would also lose a day.
  • The business quarters are different lengths. The Gregorian calendar also has business quarters of different lengths but these quarters differ even more than in the Gregorian calendar. Ideally business quarters should be the same length. If you wanted to distribute the 31-day months more evenly, the author has divised a more practical calendar like that called Luni-solar Modified Gregorian Calendar. You would still have a shorter winter quarter with three 30-day months in Nov-Dec-Jan, but it would not be any more in line with the equinoxes or solstices than the Gregorian calendar.
  • 5 day weeks would be a big adjustment, even bigger than changing the number of days in each month. But 5-day weeks are not a requirement for this calendar. And as the author of the calendarsaid, both 5- and 7-day weeks could be observed simultaneously while people got used to the idea. So they could decide later to scrap it if it didn't catch on.

Similar Calendars[]

Daylight Saving Time Standardization option[]

Daylight saving time came into effect because the days in the spring and summer are longer than the nights, and so politicians realized that by setting the clocks ahead 1 hour, an hour of morning daylight would be shifted to the evenings. And since its implementation it has been shown to save energy because people don't have to use as much electricity in the evenings and are generally asleep and not using electricity in the mornings. But not everyone has been able to agree on exactly when daylight saving time should be implemented if at all.

Since the days are not longer than the nights until the equinoxes, the author of the calendar suggests that daylight saving time be standardized so that time changes always occur on the Sundays closest to the equinoxes worldwide. This would make the day of setting clocks the same day in the Northern Hemisphere as in the Southern Hemisphere, making it standard for the first time worldwide. Daylight saving time in the northern hemisphere would be 6 months instead of the current 7 months or so. The southern hemisphere would also get to enjoy a similar 6 months of daylight saving time instead of the current 4 months or so.

The author of the calendar proposes that on the Sundays nearest the equinoxes that each country or region that observes daylight saving time change their clocks at 2am local time.

Either that or just make Daylight Saving Time year round. the author of the calendar thinks most people would like that idea because he for one don't like having to change his clocks.