Load-in and Load-out
The windows for vendors to bring gear in before, and remove it after, your event.
Load-in is the time vendors are allowed to arrive and set up equipment, decor, and rentals; load-out is the time they must strike everything and clear the space afterward. Venues define both in the contract.
Tight windows drive real costs, especially for rental companies delivering large items. Confirm these times early and share them with every vendor.