A store closes the same time everyday. About ten minutes before closing an annoucement is made to let customers know the store is about to close. Anyone entering after annoucement is greeted and told the store will be closing in ( number) minutes. If someone comes in at two minutes to closing and is told they have two minutes how long do you wait.

Usually, I first close, not letting any new people in, and then give them 5 - 10 minutes.

If it's a BIG store (best buy... home depot... etc), most likely... 10 min is necessary. At 5 minutes, I'd put on the announcement that the store is now closed, bring up your final purchases to the register, etc.

Where I used to work at closing time we would lock the door no one comes in I would have to stand at the door to let people out and our manager would tell people time to go store is closed

Yes, for our little store we wait on the customer to help them finish their shopping. And just wait till they are done.

But as in larger stores, they wait that 10 min or so.