Time pocket

What ever you need or want you can grab it from the past or future. But the item goes back the exact moment and exact placement from its own time; The moment it has been used.  If permanency has been cast on it or it has been in the current time line more then 12 hours an exact copy is sent back to replace that item. (To be more clear if you grab an arrow that will kill the king when the arrow is replaced or returned it will still kill the king but you will still have the arrow that was meant to kill the king.)