Our schedules are kept on-time with roughly 20 minute sessions. Here's a typical Grand Bend Motorplex day.

8 AM: staff arrival, begin setup
8:45 AM: Track is cleared of staff, staff arrive at posts
9 AM: Driver's meeting (first one; if you miss this one, you will lose track time until the second driver's meeting)
Approximately 9:20 AM: Lead-follow exercise begins
Approximately 9:40 AM: yellow run group begins lapping
10 AM: blue run group begins lapping
10:20 AM: green run group begins lapping
10:40 AM: yellow group runs again
...
4:20 PM: All run groups on track at once, since fewer people will be at the track (happy hour)