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Name: Lawrence Hixson
Email: [EMAIL PROTECTED]
Homepage: http://aquacade.net
UserID: aquacade
I'd like to contribute a module for Julian Day (JD) number
to/from conversions that are absolutely accurate from 1/1/9999 BC to 12/31/9999
AD to the second (perhaps a wider range of years if my testing proves the
routines reliable).
My module differs from other CPAN contributions in that
it:
1) Assumes our current 7-day week as a continuous series of
days from ancient to future, completely incorporating full rules of leap years
as though leap year rules existed across the range of all years as
well.
2) It uses fractional part of number to encode time of day to
the second
3) Uses 12:00:00 UTC as it's change of day as per it's
intended purpose (astronomical observations done during night so midnight is JD
fraction .5
4) JD 0 is 1/1/4713 BC 12:00:00 UTC
5) For ease of use I assume that non-existent year zero is
treated as 1 BC and the Gregorian shift is handled seemlessly by forcing all the
days from 5-OCT-1582 to 14-OCT-1582 to JD 2299161 to maintain unbroken 7-day
weeks
6) Day-of-the-week function included due to 12:00:00 UTC
bias as $dow=abs(floor($jd+.5)) % 7
7) Day-of-the-year function also included.
I will probably include a few other date/time related function
(not parsing) as yet to be determined.
Thanks! |
