faixa de calendário
>>> _, num_days = calendar.monthrange(2016, 3)
>>> first_day = datetime.date(2016, 3, 1)
>>> last_day = datetime.date(2016, 3, num_days)
>>> first_day
datetime.date(2016, 3, 1)
>>> last_day
datetime.date(2016, 3, 31)
Harish Vasanth