How long will the Apple store hold my items for pickup?

It generally ranges from 3 days up to a week. If you contact the store they may be able to hold it a day or two longer. Definitive answers will come from store personnel.

Certainly every store is diffrent. (Local regulations, staffing levels, readily-accessible storage space, etc.)

So +1 to contact the store manager pre-order to discuss the possibilities.

This is a user to user only forum. You'd need to contact the store and ask them, if you don't think you can pick up the item when it is ready for pickup. I've heard of stores holding an item for a few days, but they won't hold it indefinitely. So contact the store and ask them.

19 minutes and 28 seconds or possibly forever.

You might want to contact the store and ask.