Convert UTC DateTime to another Time Zone

c# datetime timezone dst
Mark Richman picture Mark Richman · Mar 30, 2010 · Viewed 60.4k times · Source

I have a UTC DateTime value coming from a database record. I also have a user-specified time zone (an instance of TimeZoneInfo). How do I convert that UTC DateTime to the user's local time zone? Also, how do I determine if the user-specified time zone is currently observing DST? I'm using .NET 3.5.

Thanks, Mark

Answer

Matt Johnson-Pint picture Matt Johnson-Pint · Jun 5, 2014

The best way to do this is simply to use TimeZoneInfo.ConvertTimeFromUtc.

// you said you had these already
DateTime utc = new DateTime(2014, 6, 4, 12, 34, 0);
TimeZoneInfo tzi = TimeZoneInfo.FindSystemTimeZoneById("Pacific Standard Time");

// it's a simple one-liner
DateTime pacific = TimeZoneInfo.ConvertTimeFromUtc(utc, tzi);

The only catch is that the incoming DateTime value may not have the DateTimeKind.Local kind. It must either be Utc, or Unspecified.

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