A meta-misconception: It's possible to establish a total ordering on timestamps that is useful outside your system.
Virtual machines can be screwed with comprehensively. So can non-virtual ones, come to that, and your software likely isn't in a position to tell that it's already seen 02:34:17 GMT 2013-05-25 five times already.
So what can you do about that? Bloody nothing. Absolutely nothing whatsoever. You're screwed. Everything you could do can be screwed with in ways your program can't defend against.
The lesson: Don't worry about bugs you can't fix. Refusing to play games you can't win will keep your hair in your head a lot better than knowing the intricacies of human timekeeping systems past and present.
Virtual machines can be screwed with comprehensively. So can non-virtual ones, come to that, and your software likely isn't in a position to tell that it's already seen 02:34:17 GMT 2013-05-25 five times already.
So what can you do about that? Bloody nothing. Absolutely nothing whatsoever. You're screwed. Everything you could do can be screwed with in ways your program can't defend against.
The lesson: Don't worry about bugs you can't fix. Refusing to play games you can't win will keep your hair in your head a lot better than knowing the intricacies of human timekeeping systems past and present.