Time gating is a feature of a game where progress is limited by real-life time constraints imposed by the developers. For example, there might be a quest that you can only do once per week. Of real time, not game time.
Time gating is NOT a game where a time limit is part of the rules. Say a game lasts X minutes and you have to score as many points as possible in that time. That's not time gating. Time gating would be if you can only play that game 5 times per day and then have to wait until tomorrow to play again.
Time gating is very common in "free-to-play" games where you can bypass the time gate by purchasing FunBux with real money. It's also common in MMOs. It's one huge reason I can't stick with any MMO very long; I feel like I'm being manipulated or controlled, usually to try to squeeze revenue out of me.
My opinion: There is no game where time gating results in the game being more fun rather than less fun. Can you think of a counterexample? A game where time gating adds fun?