5 Minutes Early Is On Time; On Time Is Late; Late Is Unacceptable - Maj Peter Colquhoun, Australian Army
And of course if you're going to show up 5 minutes early to be on time, and there are uncertainties (reducible or irreducible) along to way to your scheduled arrival, then you're going to need to estimate what those uncertainties are, how they impact your arrival confidence, and then estimate how your corrective or preventive actions will increase the probability of showing up 5 minutes early.
