I downloaded and tested a few dates with the Win32 executable of Jalali (the one at sourceforge). The bad news is that, the conversion is not correct. The conversion is wrong for 20 March 2005, and similarly a few other dates that should convert to 30 Esfand Year YYLP, instead all such dates convert either to 1 Farvardin YYLP or 1 Esfand YYLP, depending on how the date os set to 20 March 2005. The good news is that, the jalali.c source does convert such dates correctly.
On Mon, 24 May 2004 02:19:09 -0400, Behdad Esfahbod <[EMAIL PROTECTED]> wrote: > > > So, to conclude, I think we better don't touch the 33 > implementations we have until we've got a real calendar. Just > talking about FarsiWeb of course. Other people are free about > what they choose. > > behdad > > > > On Mon, 24 May 2004, Ordak D. Coward wrote: > > > I did some more research on the accuracy of different leap year > > algorithms. My conclusion is that unless there is an implementation of > > an astronomical algorithm, we SHALL use the 33 year period, as it > > gives the best estimates for near future and near past. That is, use > > the following: > > bool isLeapYear = ((y*8+29)%33) < 8; > > > > I used the following table of vernal equinox times for years 1788-2011: > > http://www.newscotland1398.net/equinox/vern1788.html > > I computed the length of year for each year. and unfortunately, I > > could not find any simple curve to fit the length of years. > > Assuming that the real vernal equinox does not differ from the table above > > by more than +/- 10 minutes, and that the noon will be at 12:04:20, > > I am convinced that this formula is correct at a minimum from 1178 to 1468. > > At the same time, the Birashk's method and hence Omid K. Rad's implementation > > are only correct from 1244 to 1402. > > > > Another way to interpret this email is that Birashk's method fails to > > correctly predict the year 1403, and hence if we use that mehtod, all > > dates in year 1404 will be off by one day. On the other hand, using > > the 33 year period mentioned above works fine until year 1468. > > > > So, for all applications that need to convert near-term dates, my > > recommendation is to use a 33-year implemntation, like the one found > > at http://www.farsiweb.info or > > the one at http://www.payvand.com/calendar/. > > > > -- > > ODC > > _______________________________________________ > > PersianComputing mailing list > > [EMAIL PROTECTED] > > http://lists.sharif.edu/mailman/listinfo/persiancomputing > > > > > > --behdad > behdad.org > _______________________________________________ PersianComputing mailing list [EMAIL PROTECTED] http://lists.sharif.edu/mailman/listinfo/persiancomputing
