7912: Add julian_easter(y) function to libholiday.py

This commit is contained in:
Vlada Perić 2014-07-17 17:22:54 -07:00 committed by Paul Franklin
parent daee6c032c
commit d8a6d2f6a8

View File

@ -74,6 +74,31 @@ def easter(year):
day = l + 28 - 31 * (month / 4) day = l + 28 - 31 * (month / 4)
return "%d/%d/%d" % (year, month, day) return "%d/%d/%d" % (year, month, day)
def julian_easter(year):
"""
Computes the year/month/day of Eastern Orthodox Easter, given in the
Gregorian calendar. Implements the Jean Meeus algorithm. Valid: 1900-2099.
"""
a = year % 4
b = year % 7
c = year % 19
d = (19*c + 15) % 30
e = (2*a + 4*b - d + 34) % 7
month = int(math.floor((d + e + 114) / 31))
day = ((d + e + 114) % 31) + 1
# produced date was in the Julian calendar, add 13 days to it
day = day + 13
if month == 3 and day > 31:
day = day - 31
month = 4
elif month == 4 and day > 30:
day = day - 30
month = 5
return "%d/%d/%d" % (year, month, day)
def passover(year): def passover(year):
""" """
Returns the date of Passover in a given Gregorian year. Returns the date of Passover in a given Gregorian year.