I was recently listening to “All We Have Is Now” by Flaming Lips and realized there’s something peculiar about the idea of someone time traveling with a watch. This, in turn, lead me to the following thought experiment: Suppose you had a watch that perfectly recorded the passage of time (hours, days, years, etc.) to whatever precision you wanted. You then travel back in time and give the watch to yourself in the past. Regardless of the fact that the watch itself has no origin, what time does it read?