UTC timestamp in millisecond using C++ under Windows

How do I get the UTC time in milliseconds under the Windows platform?

I am using the standard libr开发者_运维知识库ary which give me UTC time in seconds. I want to get the time in milliseconds. Is there a reference of another library which give me the accurate UTC time in milliseconds?

Use GetSystemTime API function, or perhaps GetSystemTimeAsFileTime if you want a single number.

GetSystemTime() produces a UTC time stamp with millisecond resolution. Accuracy however is far worse, the clock usually updates at 15.625 millisecond intervals on most Windows machines. There isn't much point in chasing improved accuracy, any clock that provides an absolute time stamp is subject to drift. You'd need dedicated hardware, usually a GPS radio clock, to get something better. Which are hard to use properly on a non-realtime multi-tasking operating system. Worst-case latency can be as much as 200 milliseconds.