In scheduling, patients are given a specific appointment time for the first half of the hour, leaving the second half of the hour is open for walk-in patients.

This can be in the form of modified wave scheduling wherein patients are scheduled in 15-minute increments, but two patients are booked for the first time slot of each hour. A catch-up period is built into the schedule at 9:45 a.m., 10:45 a.m. and 11:45 a.m. During this time, no appointments are scheduled.