This seems like a simple matter, but apparently it is controversial: Is it meaningful to talk about probabilities for temporal uncertainty? If I find myself in a room without a clock, I might wonder what time it is. I know that I entered the room at 9:00, so it has to be later than that. I know that someone will come for me at 12:00, so it has to be earlier than that. So the current time is somewhere between 9:00 and 12:00. So it's something that I'm uncertain about. Is it possible to quantify my uncertainty via a probability distribution? The reason why some people would say that it's undefined because "the current time" is not a random variable. On the other hand, it seems that it is perfectly meaningful to reason about the uncertainty. For example, I started working on a crossword puzzle when I first came in, and I just finished. I know from experience that there is a probability distribution on the length of time it takes me to finish a crossword puzzle, highly peaked at 1 hour. So I could use that fact to reason that it's more likely that it's 10:00 now, rather than 9:15 or 10:45.