Mostly mentioning in case you've maybe used it by mistake: You can set time via the console, I think the command is st
st 36 04 00
or some such might bring you "back" to 36.
I don't recommend messing with the time, though, even in this case; it may mess up timers (spawns, tree/plant growth, hordes etc etc). And potentially do other weird stuff.
For the time stop: In the pause menu while in DM, you can set "ticks", the speed of time for the game. I think default for that is 5, that might restore your clock. If it's set at 0, that's your likely culprit, but resetting that anyway should be relatively safe.