def time_zone(value):
    if dt_util.get_time_zone(value) is not None:
        return value
    raise vol.Invalid(
        'Invalid time zone passed in. Valid options can be found here: '
        'http://en.wikipedia.org/wiki/List_of_tz_database_time_zones')
Validate timezone.
dataset/ETHPy150Open home-assistant/home-assistant/homeassistant/helpers/config_validation.py/time_zone