Yes, it is possible to set a deadline for pre-orders; however, the deadline has nothing to do with the Picaboo Yearbooks web application.
The deadline is set and managed by the adviser. For example, the adviser should select a date that would allow plenty of time for orders while still allowing no fewer than three full weeks prior to the desired delivery date.
The adviser should use the selected deadline on all yearbook flyers and other promotional materials.
The day after the deadline, the adviser should then release the pre-order queue and place the bulk order. The storefront will switch to Immediate Order at that time.