public static DateTime FromTZToLocal(this DateTime date_, DisplayTimeZone zone_)
 {
   return TimeZoneHelper.ConvertDateTime(date_, zone_.GetTZInfo(), TimeZoneInfo.Local);
 }
 public static DateTime ToGMTFromTZ(this DateTime date_, DisplayTimeZone zone_)
 {
   return TimeZoneHelper.ConvertDateTime(date_, zone_.GetTZInfo(), TimeZoneInfo.Utc);
 }
 public static DateTime ToTZfromLocal(this DateTime date_, DisplayTimeZone zone_)
 {
   return TimeZoneHelper.ConvertDateTime(date_, TimeZoneInfo.Local, zone_.GetTZInfo());
 }