Utility to get all official public holidays in Poland for a given year.

feasts_pl.py

from datetime import date, timedelta

FEASTS = (
  (1, 1),     # New Years Day
  (1, 6),     # Epiphany
  (5, 1),     # Work Day
  (5, 3),     # Constiturion Day
  (8, 15),    # Army Day
  (11, 1),    # All Saints
  (11, 11),   # Independence Day
  (12, 25),   # Christmas
  (12, 26),   # Christmas
)

def get_easter(year):
    '''
    Returns Easter as a date object.
    '''
    a = year % 19
    b = year // 100
    c = year % 100
    d = (19 * a + b - b // 4 - ((b - (b + 8) // 25 + 1) // 3) + 15) % 30
    e = (32 + 2 * (b % 4) + 2 * (c // 4) - d - (c % 4)) % 7
    f = d + e - 7 * ((a + 11 * d + 22 * e) // 451) + 114
    month = f // 31
    day = f % 31 + 1    
    return date(year, month, day)

def get_moving_feasts(year):
    '''
    Returns all moving feasts in Polish calendar for given year.
    '''
    easter_sunday = get_easter(year)
    easter_monday = easter_sunday + timedelta(days=1)
    
    # get Pentecost
    pentecost = easter_sunday + timedelta(days=49)
    
    # get Corpus Christi
    corpus_christi = easter_sunday + timedelta(days=60)
    
    return (
      easter_sunday,
      easter_monday,
      pentecost,
      corpus_christi,
    )

def get_feasts(year):
    '''
    Returns all feasts in Polish calendar for given year.
    '''
    feasts = map(lambda x: date(year, x[0], x[1]), FEASTS)
    return tuple(feasts) + get_moving_feasts(year)