I usually dislike these questions but here goes...
I watched a TV show where a team had the ability to time travel, but I seem to remember it was either unreliable technology. Perhaps they only had a limited time and could only travel into the near past/future.
At one point I'm fairly sure one of the team tried to bring the lottery numbers home. This is why I don't believe was Sliders.
I suspect it was on British TV around 1990-1995?