Set up Available Times to only enable requests for set periods of time.
Available Times are set within a Request Profile.
Go to Teams. Select a Request Setting. Navigate to Profiles. You may edit an existing one or create a new one. Regardless, you will encounter a section labelled "Available Times".
Always: Assigned by default for any new request profile. This means that items with this enabled Request Profile will be available for request 24/7.
Between (Custom): Reduce the window of request availability for the associated items by using the "Between" settings.
Simply select your start and end times. For example, selecting "8:00" and "13:00" would only allow guests submit/order the Request Profile's items from 8:00-13:00.