Jupiter is only one light hour from the sun (~660+ million miles). I takes a radio signal about an hour to get to Jupiter from earth. We see events on Jupiter about 1 hour after they have happened. That's not so long.
Well, a back-of-the-envelope calculation says 660 million miles is about 660 thousand time zones which is about 75 years. That is a fairly long time, although I don’t know which side of the dateline they’re on, so they may actually be ahead of us.