6/1/2011 4:08:40 PM Local
6/1/2011 4:08:40 PM Utc
from
DateTime dt = DateTime.Now;
Console.WriteLine("{0} {1}", dt, dt.Kind);
DateTime ut = DateTime.SpecifyKind(dt, DateTimeKind.Utc);
Console.WriteLine("{0} {1}", ut, ut.Kind);
Use the DateTime.SpecifyKind static method.
Creates a new DateTime object that has the same number of ticks as the specified DateTime, but is designated as either local time, Coordinated Universal Time (UTC), or neither, as indicated by the specified DateTimeKind value.
Example:
DateTime dateTime = DateTime.Now;
DateTime other = DateTime.SpecifyKind(dateTime, DateTimeKind.Utc);
Console.WriteLine(dateTime + " " + dateTime.Kind); // 6/1/2011 4:14:54 PM Local
Console.WriteLine(other + " " + other.Kind); // 6/1/2011 4:14:54 PM Utc
Use the DateTime.ToUniversalTime method.
You can use the overloaded constructor of DateTime:
DateTime utcDateTime = new DateTime(dateTime.Year, dateTime.Month, dateTime.Day, dateTime.Hour, dateTime.Minute, dateTime.Second, DateTimeKind.Utc);
Source: Stackoverflow.com