Hamilton watch khaki navy gmt the navy gmt timepiece by hamilton is exceptionally functional and resilient the watch is equipped with swiss made eta 2893 1 automatic calibre that performs 28 800 vibrations per hour and has 21 bearing jewels a semi circular aperture is used to display information about the second time zone the watch comes with a special internal bezel that marks elapsed time a date display is positioned at the 3 o clock mark hands and indices are luminous for improved night