Yes, under certain conditions, this is possible. Assume you have two pickup IDs:
SRPID-1001 - Five shipments are scheduled for pickup on the same day.
SRPID-1002 - Three shipments are scheduled for next-day pickup.
When the courier arrives to pick up the shipments with pickup SRPID - 1001, he also picks up two shipments with pickup SRPID-1002 because they were also ready at the time. In this particular case, two of the three shipments from SRPID-1002 will be moved to SRPID- 1001.