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Diffstat (limited to 'python/dateutil/easter.py')
-rw-r--r-- | python/dateutil/easter.py | 89 |
1 files changed, 0 insertions, 89 deletions
diff --git a/python/dateutil/easter.py b/python/dateutil/easter.py deleted file mode 100644 index e4def97..0000000 --- a/python/dateutil/easter.py +++ /dev/null @@ -1,89 +0,0 @@ -# -*- coding: utf-8 -*- -""" -This module offers a generic easter computing method for any given year, using -Western, Orthodox or Julian algorithms. -""" - -import datetime - -__all__ = ["easter", "EASTER_JULIAN", "EASTER_ORTHODOX", "EASTER_WESTERN"] - -EASTER_JULIAN = 1 -EASTER_ORTHODOX = 2 -EASTER_WESTERN = 3 - - -def easter(year, method=EASTER_WESTERN): - """ - This method was ported from the work done by GM Arts, - on top of the algorithm by Claus Tondering, which was - based in part on the algorithm of Ouding (1940), as - quoted in "Explanatory Supplement to the Astronomical - Almanac", P. Kenneth Seidelmann, editor. - - This algorithm implements three different easter - calculation methods: - - 1 - Original calculation in Julian calendar, valid in - dates after 326 AD - 2 - Original method, with date converted to Gregorian - calendar, valid in years 1583 to 4099 - 3 - Revised method, in Gregorian calendar, valid in - years 1583 to 4099 as well - - These methods are represented by the constants: - - * ``EASTER_JULIAN = 1`` - * ``EASTER_ORTHODOX = 2`` - * ``EASTER_WESTERN = 3`` - - The default method is method 3. - - More about the algorithm may be found at: - - http://users.chariot.net.au/~gmarts/eastalg.htm - - and - - http://www.tondering.dk/claus/calendar.html - - """ - - if not (1 <= method <= 3): - raise ValueError("invalid method") - - # g - Golden year - 1 - # c - Century - # h - (23 - Epact) mod 30 - # i - Number of days from March 21 to Paschal Full Moon - # j - Weekday for PFM (0=Sunday, etc) - # p - Number of days from March 21 to Sunday on or before PFM - # (-6 to 28 methods 1 & 3, to 56 for method 2) - # e - Extra days to add for method 2 (converting Julian - # date to Gregorian date) - - y = year - g = y % 19 - e = 0 - if method < 3: - # Old method - i = (19*g + 15) % 30 - j = (y + y//4 + i) % 7 - if method == 2: - # Extra dates to convert Julian to Gregorian date - e = 10 - if y > 1600: - e = e + y//100 - 16 - (y//100 - 16)//4 - else: - # New method - c = y//100 - h = (c - c//4 - (8*c + 13)//25 + 19*g + 15) % 30 - i = h - (h//28)*(1 - (h//28)*(29//(h + 1))*((21 - g)//11)) - j = (y + y//4 + i + 2 - c + c//4) % 7 - - # p can be from -6 to 56 corresponding to dates 22 March to 23 May - # (later dates apply to method 2, although 23 May never actually occurs) - p = i - j + e - d = 1 + (p + 27 + (p + 6)//40) % 31 - m = 3 + (p + 26)//30 - return datetime.date(int(y), int(m), int(d)) |