alt Hacker NewsI work in a university environment.
The teaching model is much like that proposed by the originator of this thread. Classes are 50 minutes instead of an hour (and similar for 1.5 hour classes). The start time is 5 minutes past the hour and the end time is 5 minutes before the hour. This gives students and professors enough time to get from one lecture to another (unless they have to commute across a big campus, in which case they simply do not sign up for classes that are too close in time).
I've served on a big committee on campus that solve the timing problem simply. It starts exactly on time. Every item has a designated number of minutes. And if it appears that we will not finish on time, there is a vote on whether to extend the meeting by 30 minutes.
I realize that a lot of the discussion on this thread involves bosses and employees, which is quite a different thing, of course. There's no point in starting a meeting at a designated time if the big boss is running late.
That is because the purpose of meeting is often only to keep the big boss informed of what their team is doing. The team can operate without the meeting. The big boss cannot. Their job is to know what their team is doing.