Return Value

The difference, measured in milliseconds, between the corrected current time and midnight, January 1, 0001.

This method guarantees that the time never "goes back". More specifically, when called twice on the same thread, the second call will never return a value that is less then the value returned by the first call. If a system time correction becomes necessary, an attempt will be made to gradually compensate the returned value, so in the long run the value returned by this method is the same as the system time.