Pacific Standard

If you travel regularly, you understand that figuring out what time it is where you are, where you are going and where you started can be a real challenge.

Yet, time is essential to travel — planes are scheduled to the minute, and on the traveler’s side, it’s important to know what time it is no matter what part of the world you are in, so you don’t miss your flight or you make sure you are on time for that important meeting. Also, you need to know what time it is back home so you don’t call and wake people up in the middle of the night.

Trying to do all that with an ordinary single-time-zone watch is challenging, involving mathematics and mental gymnastics not so easily accomplished when jet lagged.

That’s where time zone watches, also known as dual time, world time or GMT/UTC watches, come in. These watches have a way to display at least two time zones to make things easier on travelers, doing the calculations required to figure out time zones for you, so the hardest decision you have to make is which watch to buy.

A Little History

The time zones we know today have been around only about a century. Before the advent of standard time in 1918, every city and region in the world operated on local solar time or apparent solar time (sun time). Most cities around the world had some sort of timekeeper, a clock chime, a whistle or a bell, to which people could synchronize their clocks and pocket watches. Back then, in a city like Los Angeles, local time could vary as much as a minute or more from one side of the city to the other due to the sun’s relative position in the sky. For example, sun time differed by about 30 seconds between the two ends of the San Francisco-Oakland Bridge. When it was 12 noon in New York City, it was 12:12 p.m. in Boston, Massachusetts; 11:56 a.m. in Philadelphia, Pennsylvania; and 11:30 a.m. in Cleveland, Ohio.

The federal government officially adopted Standard Time on March 19, 1918. By 1929, most countries around the world started keeping time by this system. In 1972, the majority of the world adopted Coordinated Universal Time, the primary time by which computer servers, mobile devices and other online services run on, and now official time zones are indicated by +/- UTC, rather than GMT. There are, however, some parts of the world that divide up time differently than originally conceived.

Newfoundland, India, Iran, Afghanistan, Venezuela, Burma, the Marquesas, as well as parts of Australia use half-hour deviations from standard time, and some nations, such as Nepal, and some provinces, like the Chatham Islands, use quarter-hour deviations.

The country with the most time zones is Russia, with 11 (due to its size), while the United States uses nine standard time zones. Two large countries, China (which should have five time zones) and India, don’t use Coordinated Universal Time and only have one time zone.

What to Look for in a Time Zone Watch

There are a number of ways that timepieces display more than one time zone, and the one that suits you best depends on how many time zones you traverse. Dual time watches use two dials, one above the other, while others use a small subdial on the main dial, which indicates home time, allowing you to set the bigger display to the time where you are staying. GMT watches use a separate pointer hand to point to the second time zone or to GMT/UTC.

Sometimes the different time zones are displayed on the dial of the watch, on a ring around the dial or on the bezel, or there might be an electronic display that will show the world time zones. In addition, there are watches which have a day/night indicator — very helpful so you don’t call someone in the middle of the night.

If you are a serious world traveler, consider a world time watch, one that displays the standard 24 hour time zones.