odometer:
... Yes, I know, this doesn't help us if only the time of day gets messed up, but it's a start, at least.
You can check if it's dark, and check the direction of the light if it's not. That'll give you am/pm and day or night. I understand there ways to check the time the sky is light vs dark over a few days to obtain the date ± a day or so. That gives you about 6 hours / year, which is within 0.07% of the true time of year.
Am I right on this?