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It’s About Time

Keeping Track of Time Around the World Requires a Complex Algorithm

Keeping Track of Time Around the World Requires a Complex Algorithm

One of the most common elements of broadcast continuity is the time check. Listeners have long considered radio stations to be primary keepers of accurate time (along with the phone company), relying on broadcasts frequently throughout their day in order to keep on schedule.

Yet as local broadcasters serve ever-widening audiences via consolidation, networking and the Internet, another chronological challenge arises, in which the tradition of addressing listeners only within a single time zone has given way to a broader range of possibilities.

As the world thus grows smaller, it behooves broadcasters to understand the workings of the world’s clocks. This is harder than it sounds. While we all understand the theoretical concept of time zones, in actual practice, international time seems to have more quirks and anomalies than the U.S. tax code.


The concept of dividing the world into 24 slices of 15 longitudinal degrees each, and setting each of the resulting zones an hour apart, is attributed to the Canadian engineer Sanford Fleming (1827-1915).

Born in Scotland and trained as a surveyor, he immigrated to Canada and eventually became the chief engineer of its Northern Railroad. He was the first to propose a transcontinental railway for Canada. As he later led its construction, he realized that in order to manage track usage efficiently and avoid collisions, a standardized method of timekeeping would be required from coast to coast. (Previously, each town had set its own local time based on the sun’s position there; as we described in the Dec. 18 issue.)

His thinking led to an international proposal for standardized zonal time, based on the observation that the earth’s rotational speed was 15 degrees per hour. His plan was adopted by 27 countries in 1884, and earned him knighthood by Queen Victoria in 1897.

The 1884 agreement also set the world’s time reference and Prime Meridian (0 degrees longitude) at Britain’s Royal Observatory in the London suburb of Greenwich, England. This selection had the additional advantage of placing the 180 degree meridian, which would serve as the day-boundary (later named the International Date Line), out in the mid-Pacific, where it would cause the least possible upheaval. Today the Greenwich Mean Time (GMT) reference is synonymous with Universal Coordinated Time (UTC) or Zulu time.

Does anybody really know…?

Since then, Fleming’s original plan has been amended to accommodate political boundaries and commercial requirements rather than adhering strictly to the 15-degree zonal alignment. Britain had been the first country to set a national standard time in the 1840s (no doubt having some influence on Fleming’s later thinking), and following the 1884 accord, all countries began to set such national policies – although with great variation among them.

Most notable among these today are the no less than nine regions of the world that offset their time with some non-integer relationship to the standard.

Closest to home among these is “Newfie Time,” the half-hour variant that is the earliest North American continental time zone (UTC-3.5h), observed only on the island of Newfoundland, Canada. Half-hour offsets also are observed in the entire countries of India, Iran, Afghanistan and Myanmar, along with the central time zone of Australia and a few island groups in the South Pacific. Strangest of all is Nepal, which uses a 15-minute offset (UTC +5:45).

Large countries generally establish multiple zones, typically along provincial boundaries. Most notable in this respect is Russia, which has 11 distinct time zones (UTC +2 to UTC +12). At the other extreme is neighboring China, which is the largest country to observe a single national time (UTC +8). Normally such a territory would occupy at least four time zones, so this creates strange daylight hours in some areas (e.g., sunrise at the equinoxes around 5 a.m. in the country’s eastern regions but not until after 9 a.m. in west).

These variations don’t always mesh well, meaning that some time-zone intersections are non-consecutive (i.e., there is more than a one-hour time change when crossing them). Extreme among these is the Bering Strait, where the Russian side is three hours different from adjacent U.S. territory. To make matters worse, the International Date Line also runs along this boundary, so when it’s 9 a.m. Monday on Russia’s Big Diomede Island, it’s noon Sunday two miles away on Alaska’s Little Diomede.

Saving the day

While zonal time attempts to deal with variation in longitude, Daylight Saving(s) Time accommodates differences in latitude and the resulting seasonal swings in daylight differential.

Also known as “Summer Time” in many parts of the world, the concept has its roots in a 1784 essay by Benjamin Franklin. Inspired by his well-known penchant for thrift, he half-facetiously suggested the DST idea as a way to save candle wax and lamp oil. He was in Paris at the time, where the daylight differential is greater than in the United States, due to that city’s more northerly location.

This brings up another frequent misconception of Americans, who generally assume that Europe and the United States occupy similar latitudes due to their fairly matching climates from north to south. Actually, a quick check of the globe will show that there is almost no overlap in latitudes, with only the northernmost tier of U.S. states sharing latitudes with the southernmost parts of Europe. (Boston and Rome are at approximately the same latitude.) So in fact, Europe and Canada share similar daylight differentials.

DST is also subject to numerous anomalies. First, tropical locations generally do not observe it, of course, because sunrise and sunset times there remain essentially unchanged year round. Next, those areas that use DST don’t all change at the same time, producing a week or two of semiannual temporal confusion between certain regions.

Even within a single country, not all jurisdictions observe it uniformly. For example, Hawaii, American Samoa, Guam, Puerto Rico, the Virgin Islands and most of the Eastern-Time portion of Indiana stay on Standard time year-round, along with Arizona – except for its Navajo Indian Reservation, which follows DST.

Commuting across such a boundary must make life interesting for people who must cope with the seasonal shifts between the time at home and at work.

There are many more interesting idiosyncrasies to the world’s timekeeping practices, and new rules continue to be adopted (Remember “Nixon-time”?). Perhaps the best answer to the simple question of “What time is it?” is, “It depends.”