code: def get_last_day_of_month(t: datetime) -> int:
      
      tn = t + timedelta(days=32)
      tn = datetime(year=tn.year, month=tn.month, day=1)
      tt = tn - timedelta(hours=1)
      return tt.day
docs: Returns day number of the last day of the month
      :param t: datetime
      :return: int