Do you still remember the age before smartphones? Then you might also remember those tiny credit-card-sized calendars like the one shown to the right. You can't write almost anything on those and they can't remind you of things. The only purpose they have is to tell which day of each month is which week-day and when public holidays are, because unfortunately, this changes every year, so it's really hard to remember. Maybe you've ever asked yourself why this has to be so complicated: why can't it be the same every year?
If we let aside historical reasons we'll find that the week has seven days, while a year has 365 and roughly a quarter day. (365.242 according to Google.) So even if we'd change the number of days in a week to make it fit, we'd couldn't have every week be just the same length and still fit in a year. (Of course, we could also slightly decrease earth's orbit around the sun, such that we make it around exactly every 364,000 days, because then a year would be just 52 7-day weeks!)
Now, instead of messing with planetary movements, perennial calendars try to simplify the problem rather by introducing better conventions. If we make the concept of "week" a little more flexible, then we can get a calendar which is the same every year and can even get some additional benefits, such as:
- months of more even length
- quarters of more even length
- months and quarters with a more even number of workdays
- better distribution and simpler to remember public holidays
In the Gregorian calendar, each month has between 28 and 31 days, which makes between 20 and 23 working days which is not only being complicated by a different number of weekends per each month every year, but additionally by public holidays which may or may not fall on weekends. In Germany, for example, depending on the year and the date of Easter, May might have 3 public holidays. If additionally, weekends fall just right, there might only be 19 working days in May. This is especially sad, because most of Germany does not have any public holidays between May or June and the beginning of October, crating a huge holiday-gap after the Spring holiday-boom.
Anyways, here are my two favorite perennial calendars which fix those problems:
Post-Gregorian Calendar: this one's really neat, because it is just a tiny change to our existing calendar which makes a big difference with it's repercussions. This calendar simply makes the first day of every year (1st January) a Sunday by definition. Applying all the normal rules will mean that the last day of the year (31st December) will also be a Sunday. Thus, the major change is simply to have one Sunday be followed by another Sunday. Of course, this would be unacceptable to fundamental Christians, but it would be very practical, since 1st January is a public holiday in most countries anyway, which is practically quite similar to a Sunday. So 31st December would be a normal Sunday (because the day before was a Saturday) and then the 1st January would be a public holiday, where people don't work, so we can make it a Sunday as well. This simple change fixes all the dates of all the non-leap years each to its specific day-of-week.
As for the leap years, we have to apply one more trick to make them perennial, too, and this trick will be very plain: in non-leap years, 28th February is always a Tuesday and thus 1st March is a Wednesday and we simply keep it that way for the leap-years, too: 29th February becomes a public holiday which you can call an additional Tuesday or a pre-Wednesday or a Middle-of-Week-Sunday or simply "The Leap Day". This might seem quite revolting to conservative people, but it is not much more revolt as having a "double hour" every time we switch back from daylight saving time or having a "date boundary" in the Pacific where on one side it's always one day later than on the other side.
If you think about this more, then the point of the Post-Gregorian calendar is not having an extra day in one or two weeks a year (because all perennial calendars need to have something like that), but the Post-Gregorian's specialty is to put those extra days in places where they least disturb ordinary, conservative life.
Now, after accepting non-weekday Leap Days and the Special "New Year's Day", we can simplify things a bit more and introduce...
The World Calendar. This one's actually been promoted for real and even been discussed at the United Nations. First published by the American Elisabeth Achelis it is one of many proposals that came up after the 18th and 19th centuries when the French Revolutionary calendar was actually made the official calendar of a powerful and modern state. But back to the World Calendar, which is so simple and beautiful that you must love it. It inserts an out-of-week day at the end of every year as well as between the second and third quarters (that is, between 30th June and 1st July) on all the leap years.
Unlike previous calendar reforms, the World Calendar keeps the names for the twelve months and simply makes the months 31, 30, and 30 days long in each quarter. In recognizing quarter-years as important periods for modern-day business it departs from previous proposals which were more focused on the seasons and agriculture.
Since each quarter in the World Calendar is the same (and is the same every year) it can be conveniently expressed with the simple table shown here (which I shamelessly copied from Wikipedia). Also note that the months have 22, 22, and 21 work-days in each quarter. So if we had 8 public holidays to spread around the calendar (which is a pretty common number in many countries), we could place them all in the 22-workday-months and obtain a calendar in which every month has exactly 21 working days. (I leave it as an exercise to the reader to find historically significant dates in his or her country which match that pattern.)
There are other Calendars which I also like a lot, especially when they come up with more meaningful names for the months and with more meaningful and less dogmatic public holidays, but I will leave this topic to another post.
To conclude, I only want to mention one type of perennial calendar which I distinctly don't like and that's any calendar which uses leap weeks instead of leap days. Leap weeks were introduced so that the religious seven-day cycle is never broken, hoping that dogmatically religious people will then accept calendar reform. But I think this line of thought will just not work because many conservative people will just not accept any reform and compromising to them will makes matters only more and more and ever more complicated. For example, both calendars described above (as well as almost all other leap-day calendars) keep the same leap-year rules as the Gregorian calendar and will thus start every year on the same day as the corresponding Gregorian year. This is a very useful feature which all the leap-week calendars give up. Besides, to end on a rather subjective note, I just think an entire week popping up between the years is quite unaesthetic and not as nice as having a single public holiday every now and then.