"Official" time for other planets
Time on Mars is measured in sols.

Venus could be a little trickier, depending on your application.

I'm not aware of any timekeeping system for any other planets. There hasn't been a need for one yet. So, again depending on your application, you could come up with various different possible schemes.



Speculation (based on the OP's input regarding application):


Mercury - because of the length of the day, I doubt would-be colonists would measure time in days. They would probably use Earth time (because of communications) and also keep track of Mercury years.
Jupiter, Saturn, Uranus, Neptune - no colonization, no timekeeping