check-clocks is a brief python script that (deep) ssh's to a list of
hosts, gets their idea of what time it is, averages the times, and
exits false if any of the clocks are "too far" from the average time.

This should detect a small number of outliers well, but will have
problems if all the clocks suddenly have the same problem.

To the best of my knowledge, it is not befuddled by timezones.