Piling on, even if the actor and time source are the same, you have to be really careful about how your use "wall clock time", because if you're just asking the

Piling on, even if the actor and time source are the same, you have to be really careful about how your use "wall clock time", because if you're just asking the OS what time it is, a lot of platforms allow the clock to move backwards, not move, etc.