Unwritten built-in Delay
At the University of Michigan we have an unwritten built-in delay. Most events are assumed to start ten minutes later than advertised, such as my “9:00” AM class, for which I need not leave my office until 9:03. If you really want an even around here to start promptly, you announce a time such as 2:59:59, and people usually get the message.
Dennis S. Bernstein
IEEE control systems magazine vol. 28 no. 1