[Bobcats 9108]

The refs jurisdiction begins as soon as he steps on the playing floor and ends when he leaves the playing floor.

I could be mistaken...
I think most refs generally don't walk out until 15 minutes or so, but if they stroll out at 19 minutes and see a dunk they are within their rights to call a T.

They can also call one after the clock hits 0 and a coach runs them down before they get off the floor.

Official jurisdiction begins when the walk on the floor at 15 minutes. That is NFHS rules don't know about college.