GMT watches are all the rage. Everybody wants one. Or two, or three. Watchmakers have obliged and seemingly every brand and its cousin has announced new takes on this horological complication lately. Why? Is it a fad? No, the GMT is popular for good reason — or, rather, for multiple reasons. GMT watches have a long and storied history but the short explanation of their enduring popularity goes like this: they’re actually useful, and in more ways than