Hi Josiah,
On Monday, April 13, 2020 at 11:09:42 AM UTC+4:30, TiddlyTweeter wrote: > > Ciao Mohammad > > I believe the Persian calendar system is likely the most astronomically > accurate of currently used calendar systems. > That's true the first day of new year is exactly the first day of spring! > > Its based on observation, unlike Gregorian which is based on rules. > > https://www.timeanddate.com/calendar/persian-calendar.html > > Just a comment > TT > > On Monday, 13 April 2020 08:25:08 UTC+2, Mohammad wrote: >> >> Example Calendar system: Persian Calendar >> >> Like the Gregorian <https://www.projectpluto.com/calendar.htm#gregorian> >> and Julian <https://www.projectpluto.com/calendar.htm#julian>calendars, >> the Persian calendar is strictly solar in nature; that is, it matches the >> seasons very nicely (better, in fact, than any other calendar on these >> pages), but makes no real effort to reflect lunar cycles. There are twelve >> months per year, as follows. >> >> farvardin (frvrdyn) 31 days >> ordibehesht (ardybhSt) 31 days >> khordad (Krdad) 31 days >> tir (tyr) 31 days >> mordad (mrdad) 31 days >> shahrivar (Shryvr) 31 days >> mehr (mhr) 30 days >> Aban (Aban) 30 days >> Azar (AZr) 30 days >> day (dy) 30 days >> bahman (bhmn) 30 days >> esfand (asfnd) 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. >> >> The Jalali calendar uses the "exact" astronomical equinox; that is to >> say, it's based on observations. The Modern Persian calendar instead >> inserts leap years algorithmically, with a complex pattern of 683 leap days >> inserted over a cycle of 2820 years. This actually makes the Modern Persian >> calendar extremely easy to program (see the source code described here.) >> <https://www.projectpluto.com/source.htm#date_cpp>The Jalali calendar is >> a little trickier, as will be discussed below. >> > -- You received this message because you are subscribed to the Google Groups "TiddlyWiki" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/tiddlywiki/899c81c9-e515-4a12-a1fb-dfc530e07dc4%40googlegroups.com.
