What is the origin of the multiple time zone watch?
Watchmakers have come up with various ways to read different time zones at the same time, which includes everything from a double clock watch to a "universal time watch" that includes all 24 time zones. Highly functional and complex functions are now more successful than ever.
There was a time when every region, even every town, had its own local time, more or less, depending on longitude. As the new mode of transportation and railway expansion, the demand for standard time system increases.
So at the international meridian conference in Washington in 1884, delegates decided to divide the earth into twenty-four time zones. From Greenwich, prime meridian (zero degrees longitude), every area across longitude 15 ° (1 hour). This system was gradually accepted by all countries.
The first dual-zone watch has two separate cores and two dial plates. The system was later modified to remove a core and introduce a "clutch" device for the second hour. Today, because manufacturers are constantly outpacing themselves in readability and convenience, two, three, four, and sometimes multiple time zones are available. Most of these watches use a pointer form to display time in additional areas in different colors or shapes. Others prefer Windows. The wearer presses a button to select one or another time zone usually represented by the city.
Watches are usually more time zone integrates travelers favorite other functions, such as day/night or 24 hours indicator at midnight (to avoid call others), ring or to adapt to the time zone of date replace function.
The rarer "time of the world" (international standard time) watch can also display 24 time zones on a rotating disk in 24 international cities.