The Simple Lunisolar Calendar

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The Simple Lunisolar Calendar is a proposal for calendar reform by Robert Pontisso. It is a non-radical lunisolar calendar which uses the 7-day week. Each year starts from the Gregorian December 3 - January 1. Each month starts on or close to the day of the new moon. All the months have fixed lengths except the sixth, that's it. The months are named after the letters of the Greek alphabet and their names and the number of days they have are:

No.	Name	Days
1	Alpha	30
2	Beta	29
3	Gamma	30
4	Delta	29
5	Epsilon	30
6	Zeta	29 but 30 in years divisible by 5, except divisible by 200, 500 or 1000, these years are known as abundant years
7	Eta	30
8	Theta	29
9	Iota	30
10	Kappa	29
11	Lambda	30
12	Mu	29
13	Nu	30 but only comes in leap years every 3 or 2 years

The Simple Lunisolar Calendar Year 2006 (The year begins on Friday, December 30, 2005)

Alpha Mon Tue Wed Thu Fri Sat Sun 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30	Beta Mon Tue Wed Thu Fri Sat Sun 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29	Gamma Mon Tue Wed Thu Fri Sat Sun 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
Delta Mon Tue Wed Thu Fri Sat Sun 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29	Epsilon Mon Tue Wed Thu Fri Sat Sun 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30	Zeta Mon Tue Wed Thu Fri Sat Sun 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29
Eta Mon Tue Wed Thu Fri Sat Sun 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30	Theta Mon Tue Wed Thu Fri Sat Sun 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29	Iota Mon Tue Wed Thu Fri Sat Sun 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30
Kappa Mon Tue Wed Thu Fri Sat Sun 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29	Lambda Mon Tue Wed Thu Fri Sat Sun 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30	Mu Mon Tue Wed Thu Fri Sat Sun 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29

If 30 days or more are left after Mu 29 till the Gregorian new year's day then an extra month Nu is added. The Gregorian new year's day must fall in the month of Alpha. Given that December 25, 2000 is Alpha 1, 2001 the calendar continues from this date. This calendar is simple and easy to use.

This calendar cannot replace the Gregorian calendar, because it is necessary to know the Gregorian date when determining whether the year has a month Nu. It would run alongside the Gregorian Calendar much like the ISO week date calendar would. The chart on the website [1] shows the Gregorian date for the first day of each month in this calendar for the years 2001 - 2500.

The months jitter a lot because the month lengths are fixed, the abundant years non-uniformly spread and also the non-uniformity of leap years, which are caused by the fact that the Gregorian leap years are non-uniformly spread and also it's Alpha 1 that has to be on December 3 - January 1, not the actual new moon, as the months jitter.

Karl Palmen suggested the there be 20 abundant years every 103 years spread as evenly as possible, so the each abundant year occurs five years after the previous, except for three every 103 years that occur six years after the previous. These three exceptions would occur in intervals of 36, 36 and 31 years.

[edit] External link

• The Simple Lunisolar Calendar