Mechanism: The Rolex 1036 used in the Rolex GMT-Master was the first movement to permit a watch to show the time in two locations simultaneously.

Family Notes: The Rolex "Date" family of watches are smaller and less expensive than their cousins, the "Datejust" family. Date watches are enclosed in 34mm cases, whereas Datejust models are in 36mm cases. Furthermore, the Date models use 19mm width straps while the larger Datejust models use 20mm straps.

Being the less expensive line, new features reach the Date family only after the Datejust watches have already adapted them. For example, the Datejust family received mechanisms with Quickset date capability years before the Date models did.