from dateutil.parser import parse


def timestamp(date_time):
    """Convert a date string to number of seconds since 1 Jan 1970 00:00 UTC
    date: e.g. "2016-01-27 12:24:06.302724692-08"
    """
    t0 = parse("1970-01-01 00:00:00+0000")
    t = parse(date_time)
    return (t-t0).total_seconds()