

def iso_year_start(iso_year):
    ' The gregorian calendar date of the first day of the given ISO year. '
    fourth_jan = date(iso_year, 1, 4)
    delta = timedelta((fourth_jan.isoweekday() - 1))
    return (fourth_jan - delta)

dataset/ETHPy150Open caxap/redis-moment/moment/utils.py iso_year_start/original