def datetime_from_iso8601(date):
    """Small helper that parses ISO-8601 date dates.

        >>> datetime_from_iso8601("2013-04-10T12:52:39")
        datetime.datetime(2013, 4, 10, 12, 52, 39)
        >>> datetime_from_iso8601("2013-01-07T12:55:19.257")
        datetime.datetime(2013, 1, 7, 12, 55, 19, 257000)
    """
    format = ISO8610_FORMAT
    if date.endswith("Z"):
        date = date[:-1]  # Date date is UTC
    if re.match(".*\.\d+", date):
        # Date includes microseconds
        format = ISO8610_FORMAT_MICROSECONDS
    return datetime.datetime.strptime(date, format)