The Omega Seamaster Planet Ocean 600M Co-axial Master Chronometer GMT Deep Black in Red is made from a single block of ceramic
A GMT or world timer is a watch that can indicate more than one time zone. Either by a hand, often called a GMT hand (Greenwich Mean Time) or world timer hand. A pure GMT watch has a second hour hand that can indicate 12 or 24 hours depicted on a time scale on the dial or bezel. Most GMT watches display the local time in a 12-hour format and have an independently adjustable 24-hour hand to indicate the home time.
.
A world timer can show the time in a second time zone, and has the world’s 24 time zones often depicted on the dial or bezel. Mostly indicated with 24 city names. Some world timers have a rotating city disc, others a second hour hand. On some world timers there is a connection between the home time and local time hours, so if you adjust the watch to another time zone, the home time will display as well.
.
Watches with a GMT / World timer
The Breguet Classique 5717 Hora Mundi does have something handy in the form of an easy to operate time switching mechanism
A new version of the Classic Dual Time by UN: this is the Ulysse Nardin Classic Dual Time Enamel Boutique Edition
The Graham Silverstone RS GMT is named after a British circuit and honors a Swiss hill climb. And it looks pretty cool
The Ulysse Nardin Executive Moonstruck Worldtimer shows the time and movements of the Moon and Sun in relation to the Earth
The Oris Big Crown ProPilot Worldtimer is an update of the 1997 model, now with rotating bezel to set a second time zone
The Ulysse Nardin Classic Dual Time Enamel offers a second time zone without an extra hand. It is shown in a display at 9 o’clock
The Omega Seamaster Aqua Terra Worldtimer Master Chronometer is a possible precursor for an affordable Omega world timer
A new a Toric model with a complication we’ve seen on the Tonda: this is the Parmigiani Fleurier Toric Hémisphères Rétrograde
Another TimeWalker model from Montblanc, this time with three time zones. This is the Montblanc TimeWalker Chronograph UTC