Python: using dateutil’s easter() function.
>>> from dateutil.easter import *
>>> print easter(2010)
2010-04-04
>>> print easter(2011)
2011-04-24
The functions gets, as an argument, the type of calculation you like:
EASTER_JULIAN = 1
EASTER_ORTHODOX = 2
EASTER_WESTERN = 3
You can pick the one relevant to the US.
Reducing two days from the result would give you Good Friday:
>>> from datetime import timedelta
>>> d = timedelta(days=-2)
>>> easter(2011)
datetime.date(2011, 4, 24)
>>> easter(2011)+d
datetime.date(2011, 4, 22)
Oddly enough, someone was iterating this, and published the results in Wikipedia’s article about the algorithm:
