Finding monday of a week

gistfile1.py

# Given a date find the monday and friday of the week
# This assumes that the week starts on sunday
import datetime
import calendar
from dateutil.relativedelta import relativedelta

def get_monday_in_week(date):
       # Find the current week
       current_week = date.isocalendar()[1]
       delta = relativedelta(weeks=current_week-1, weekday=calendar.MONDAY)
       # Take a reference which will always be on the first
       # week of the year. Apparently the 4th of Jan is
       # always on the first week ;-)
       # proof ?
       # >>> set([date(year, 1, 4).isocalendar()[1] for year in range(2000, 2999)])
       # set([1])
       return datetime.date(date.year, 1, 4) + delta