Convert UTC DateTime to another Time Zone

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.