Tom Coughlin when he was the first manager of the Jaguars, before moving on to NY Giants, had a policy that included being on time for meetings. One day one of the better running backs was late for the team meeting by about five minutes. Seems he had an small fender bender on the way in. Coughlin reputedly told him that would be a fine (1K?). The player argued he had the accident. Coughlin told him, if you are not five minutes early for meetings you are late! I think all meetings went on from that point forward with everyone there!
Vince Lombardi time - 15 minutes before start time.