Timezoner
The names of 24 cities are displayed on the bezel; each one represents one of the international time zones. The bezel is pushed down on opposing sides with the thumb and forefinger. The desired time zone (or, during the daylight saving time, the small āSā just before the city name) is then turned to the ā12 oāclockā position. The movement of the bezel is transferred to the hour wheel, 24-hour display and date advance wheel, ensuring that all three displays can be adjusted forwards or backwards in one-hour steps. Drive for the normal movement of the hour hand and its ājumpā when the time zone is changed is provided via a differential gear.
