[Python-Dev] dateutil

[Christian Tanzer]

"Brett C." <bac at OCF.Berkeley.EDU> wrote:

>  > * Computing of Easter Sunday dates for any given year,
>  >   using Western, Orthodox or Julian algorithms;
>  >
>
> Don't really see the use in this other than the rule figuring this out
> is odd enough that I never remember.  Who really cares when Easter is
> beyond certain religious groups?

Anybody living in a part of the world with some public holidays based
on Easter. For instance, in Austria there are five of these.

BTW, I can't really see why you have such a hard time remembering:

    if 1583 <= year <= 1699 : m, n = 22, 2
    elif 1700 <= year <= 1799 : m, n = 23, 3
    elif 1800 <= year <= 1899 : m, n = 23, 4
    elif 1900 <= year <= 2099 : m, n = 24, 5
    elif 2100 <= year <= 2199 : m, n = 24, 6
    elif 2200 <= year <= 2299 : m, n = 25, 0
    else :
        raise NotImplementedError, \
              "Only implemented for years between 1583 and 2299"
    a = year % 19
    b = year %  4
    c = year %  7
    d = (19*a + m) % 30
    e = (2*b + 4*c + 6*d + n) %  7
    day = 22 + d + e
    if day <= 31 :
        month = 3
    else :
        day = d + e - 9
        month = 4
        if day in (25, 26) and d == 28 and e == 6 and a > 10 :
            day -= 7
    return (year, month, day)

<42.0 wink>

Cheers,

-- 
Christian Tanzer                                    http://www.c-tanzer.at/