Why is Rolex GMT called GMT?

Inquiring minds want to know, why is the Rolex GMT affectionately referred to as the "GMT"? Could it be because it stands for Greenwich Mean Time, the international standard for time zones, alluding to the watch's ability to display multiple time zones simultaneously? Or perhaps the GMT moniker is a nod to its rich history and association with globe-trotting adventurers and explorers who relied on its precision timekeeping? The question begs to be answered: what is the etymological genesis behind the Rolex GMT's moniker, and what does it signify within the world of luxury timepieces?