babak - 2009-09-02

Jalali is the official calendar for people in iran and as MS-Windows does not support it fully, there are great problems in having a good calendar! so i would like to see it in Rainlendar.

the rules are easy though.

A. days name are :
1. Saturday is Shahnbeh
2. Sunday is Yek Shahnbeh
3. Monday is Do Shahnbeh
4. Tuesday is Se Shahnbeh
5. Wednesday is Char Shahnbeh
6. Thursday is Panj Shahnbeh
7. Friday is jome

B.month names are:
1.Farvardin (31 days)
2.Ordibehesht (31 days)
3.Khordad (31 days)
4.Tir (31 days)
5.Mordad (31 days)
6.Shahrivar (31 days)
7.Mehr (30 days)
8.Aban (30 days)
9.Azar (30 days)
10.Day (30 days)
11.Bahman (30 days)
12.Esfand (29/30 days)
The year begins at the spring equinox. If that instant is before midday, Teheran time, then that day is 1 farvardin; otherwise, the next day is 1 farvardin. This can result in either 365 or 366 days per year. In the former (usual) case, the last month of esfand has 29 days; otherwise, it has 30 days.

C.years :

Let me tell you some facts about Jalali and Gregorian calendars. As you may know, it takes 365.2421898 days (non-integer value) for the earth to orbit the sun. We should take this into account. Gregorian and Jalali calendars have different solutions to this problem.

According to the article, Leap Years by Chris Maunder and LeRoy Baxter, the rule for the Gregorian calendar is:
Most years divisible by 4 are Leap Years (i.e. 1996 was).
However, most years divisible by 100 are NOT! (1900 was not).
Unless they are also divisible by 400 (2000 will be).
For the Jalali calendar, we can say the statements below:

Jalali calendar is cyclic with the period of 33 years. each cycle starts at the year 33k + 23 (i.e. 1376).
The first 28 years of each cycle are seven 4-year subcycles with the forth year of each subcycle being a leap year.
The last 5 years of the cycle are composed of 4 ordinary years and a fifth year being a leap year.

In jalali calendar years are counted since AD 622. At vernal equinox of that year, AP 1 started (AP = Anno Persico/Anno Persarum = Persian year). In the year AD 2009 we have therefore witnessed the start of Persian year 1388.

Please someone help in adding this feature.

here are some websites which migh be of help.
useful data:
en.wikipedia.org/wiki/Iranian_calendar
www.tondering.dk/claus/cal/node7.html

relevant codes:
www.codeproject.com/KB/cs/JalaliCalendar.aspx
www.codeproject.com/KB/datetime/Jalali_Shamsi__Calendar.aspx
http://msdn.microsoft.com/en-us/library/system.globalization.persiancalendar.aspx