You can also create a string representation of a DateTimeOffset object's millisecond component by calling the erload:System.DateTimeOffset.ToString method with the "fff" custom format specifier.

If you rely on properties such as DateTimeOffset.Now or DateTimeOffset.UtcNow to accurately track the number of elapsed milliseconds, the precision of the time's millisecond component depends on the resolution of the system clock. On Windows NT 3.5 and later, and Windows Vista operating systems, the clock's resolution is approximately 10-15 milliseconds.

Namespace: System
Assembly: mscorlib (in mscorlib.dll)
Assembly Versions: 2.0.0.0, 4.0.0.0