This method determines whether the current xtd::date_time value falls within the daylight saving time range of the local time zone, which is returned by the xtd::time_zone_info::local property. You can determine whether a time zone supports daylight saving time by retrieving the value of its xtd::time_zone_info::supports_daylight_saving_time property. For time zones that observe daylight saving time, you can determine when the transition to and from daylight saving time occurs by retrieving the xtd::time_zone_info::adjustment_rule array returned by the time zone's xtd::time_zone_info::get_adjustmen_rules property.
If the current xtd::date_time value represents either an ambiguous or an invalid time in the local time zone, the method returns false.