First of all, DateTime is stored in CRM in UTC format. So in order to get ldaylight saving info, you need to know what time zone you are doing your calculation based on. If you are doing some kind of timer or function based on the local time, you need to
know what time zone you are in to work with.
to get the local time zone, you can get either get from user profile settings, or even hard code it if you know it.. Here is a conversion code from UTC to a local time and hope it will help you.
var request = new LocalTimeFromUtcTimeRequest
{
TimeZoneCode = timeZoneCode,
UtcTime = ServerDateTime
};
var response = (LocalTimeFromUtcTimeResponse)service.Execute(request);
return response.LocalTime;
this is the list of timezone codes: https://technet.microsoft.com/en-us/library/aa226764(v=sql.80).aspx