If a selected person is unavailable during the selection cycle for a legitimate reason such as an extended absence or long-term illness, document the reason. Then make another selection or make an extra selection during the next selection cycle.
If an employee is notified on their day off, they should still report to a collection facility to complete the drug test.
If a person is selected for testing but has not received notice since it is their day off, test the person during their next shift.