Just in time, a short Python code snippet to calculate the date of Easter Sunday of a given year. This can be expanded to calculate the important date of Mardi Gras too.

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``````# calculating the date of Easter Sunday
# tested with Python24    vegaseat    16apr2006

import datetime

def calc_easter(year):
"""returns the date of Easter Sunday of the given yyyy year"""
y = year
# golden year - 1
g = y % 19
# offset
e = 0
# century
c = y/100
# h is (23 - Epact) mod 30
h = (c-c/4-(8*c+13)/25+19*g+15)%30
# number of days from March 21 to Paschal Full Moon
i = h-(h/28)*(1-(h/28)*(29/(h+1))*((21-g)/11))
# weekday for Paschal Full Moon (0=Sunday)
j = (y+y/4+i+2-c+c/4)%7
# number of days from March 21 to Sunday on or before Paschal Full Moon
# p can be from -6 to 28
p = i-j+e
d = 1+(p+27+(p+6)/40)%31
m = 3+(p+26)/30
return datetime.date(y,m,d)

# test the calc_easter function
if __name__ == '__main__':
print calc_easter(2006)                       # 2006-04-16
print calc_easter(2006).strftime("%d %B %Y")  # 16 April 2006``````