Question

i am using earth tool webservice to find time zone based on lat long. I am getting offset and suffix in the webservice.

Earth Tool Webservice

Now the problem, i am facing is i need to get time zone from the offset and suffix and determine if there is daylight saving in the area or not. how can i do this?

Answer 1

.Net has a nice TimeZoneInfo.Local.IsDaylightSavingTime, but unfortunately you don’t have enough info to create an instance.

You should however be able to do something like this:

var offSet = -7;
var utcDateTimeStr = "2011-09-10 22:15:38";
var localWithDSStr = "10 Sep 2011 15:15:38";

// utc time
DateTime utcDateTime = DateTime.SpecifyKind(
                           DateTime.Parse(utcDateTimeStr), DateTimeKind.Utc);
// time taking into account daylight savings
DateTime localWithDS = DateTime.SpecifyKind(
                           DateTime.Parse(localWithDSStr), DateTimeKind.Local);
// time not taking into account daylight savings
DateTime localWithoutDS = utcDateTime.AddHours(offSet);

// is the time given adjusted for daylight savings
TimeSpan diff = (localWithoutDS - utcDateTime);
bool isDayLightSaving = diff.Hours != offSet;