(year, week_of_year, day_of_week, week_starts_Mon)
Calculate the Julian day based on the year, week of the year, and day of
    the week, with week_start_day representing whether the week of the year
    assumes the week starts on Sunday or Monday (6 or 0).
Calculate the Julian day based on the year, week of the year, and day of
    the week, with week_start_day representing whether the week of the year
    assumes the week starts on Sunday or Monday (6 or 0).
Calculate the Julian day based on the year week of the year and day of the week with week_start_day representing whether the week of the year assumes the week starts on Sunday or Monday ( 6 or 0 ) .
def _calc_julian_from_U_or_W(year, week_of_year, day_of_week, week_starts_Mon):
    """Calculate the Julian day based on the year, week of the year, and day of
    the week, with week_start_day representing whether the week of the year
    assumes the week starts on Sunday or Monday (6 or 0)."""
    first_weekday = datetime_date(year, 1, 1).weekday()
    # If we are dealing with the %U directive (week starts on Sunday), it's
    # easier to just shift the view to Sunday being the first day of the
    # week.
    if not week_starts_Mon:
        first_weekday = (first_weekday + 1) % 7
        day_of_week = (day_of_week + 1) % 7
    # Need to watch out for a week 0 (when the first day of the year is not
    # the same as that specified by %U or %W).
    week_0_length = (7 - first_weekday) % 7
    if week_of_year == 0:
        return 1 + day_of_week - first_weekday
    else:
        days_to_week = week_0_length + (7 * (week_of_year - 1))
        return 1 + days_to_week + day_of_week
def _calc_julian_from_U_or_W ( year , week_of_year , day_of_week , week_starts_Mon ) : first_weekday = datetime_date ( year , 1 , 1 ) . weekday ( ) # If we are dealing with the %U directive (week starts on Sunday), it's # easier to just shift the view to Sunday being the first day of the # week. if not week_starts_Mon : first_weekday = ( first_weekday + 1 ) % 7 day_of_week = ( day_of_week + 1 ) % 7 # Need to watch out for a week 0 (when the first day of the year is not # the same as that specified by %U or %W). week_0_length = ( 7 - first_weekday ) % 7 if week_of_year == 0 : return 1 + day_of_week - first_weekday else : days_to_week = week_0_length + ( 7 * ( week_of_year - 1 ) ) return 1 + days_to_week + day_of_week