Named Dates (WIP)

The goal of named dates is to provide a simple API to keep track of special dates and their associated logic.

Usage

Need to recognize the 4th Thursday in November?

thanksgiving = NamedDate("Thanksgiving Day", 11, 3, nth=4,
                         aliases=["Thanksgiving", "Turkey Day"])
...
if thanksgiving.falls_on(my_date):
    print "TURKEY DAYYYYY"

How about a date based on the end of the month? Say, the last Monday in May?

NamedDate("Memorial Day", 5, 0, nth=1, from_end=True)

Something more complex? Define a custom function.

def is_good_friday(date):
    # Defaults to western Easter.
    return date == easter(date.year) - datetime.timedelta(days=2)

NamedDate("Good Friday", custom_func=is_good_friday)

You can even group important dates into sets, find out which dates are in a set, and find out whether a date is in a set.

company_holidays = NamedDates([NamedDate("Christmas", 12, 25),
                               NamedDate("New Years", 1, 1)])
company_holidays.add(thanksgiving)

my_date = datetime.date(2015, 12, 25)
assert company_holidays.observes(my_date)
assert company_holidays["Christmas"].falls_on(my_date)