BulldogLowell:
OP isn't asking for something that crazy/unreasonable.
But just because the software will dutifully deliver time in milliseconds doesn't mean the time has been synced properly. That is my point. I wasn't asking what it was needed for, there are many applications. GPS will get you much closer than SNTP if you are hoping for actual millisecond accuracy.
Perhaps my question should have been, exactly how much accuracy do you require?