Hi -

Gotta be careful with the wording: calibration is comparing something to a standard, while hacking (in this context) means that the time-keeping character of a watch is stopped in order to synchronize it.

Calibrating a watch is more than synchronizing it: it means that it will keep the same kind of time as the source clock, i.e. will maintain the same accuracy, more or less, between the two watches. High-quality aviation watches were like this before the advent of computer-controlled aviation: if you were trying to synchronize 1000 planes on top of a target which included a 6 hour flight just to get there, you want all the watches worn by the lead pilots to show the same time-keeping characteristics, so that when everyone is supposed to be over the target, no one is more than a few seconds off. This was, back when, a LOT easier said than done, and simply synchronizing watches wasn't enough: you had to calibrate them.

I know this is fairly pedantic in this day and age, but the difference is subtle, but important...