ST. PETERSBURG, February 10 (Itar-Tass) -- Russia was amongst 25 countries, which initiated standardized time zones on the Earth, press secretary of the Russian Academy of Sciences’ Main Astronomical Observatory (Pulkovo) Sergei Smirnov told Itar-Tass.

Precisely 90 years ago the Soviet government authorized the switch to standard time zones in Russia.

In 1884, an International Prime Meridian Conference was held in Washington D.C. to adopt the standardized method of time keeping and to determine the location of the Prime Meridian. Conference members agreed that the longitude of Greenwich, England, would become the zero degrees longitude and established 24 time zones relative to the Prime Meridian. It was also proposed that the measurement of time on the Earth would be made relative to the astronomical measurements at the Royal Observatory at Greenwich. This time standard was called Greenwich Mean Time (GMT).

In 1878, a Canadian, Sir Sanford Fleming, suggested a system of worldwide time zones that would simplify the keeping of time across the Earth. Fleming proposed that the planet be divided into 24 time zones, each 15 degrees of longitude in width. Since the world rotates once every 24 hours on its axis and there are 360 degrees of longitude, each hour of Earth rotation represents 15 degrees of longitude.

Railroad companies in Canada and the United States began using Fleming's time zones in 1883. The two states and France fully adopted standardized time in 1911 and Russia followed the suit eight years later. Prior to that, Russia set clocks according to the moving Sun and switched to universal St. Petersburg time in order to meet railroad schedules afterwards.

Today, many nations operate on variations of the time zones suggested by Sir Fleming. Figure 2c-1 describes the various time zones currently used on the Earth. In this system, time in the various zones is measured relative the Coordinated Universal Time (UTC) standard at the Prime Meridian. Coordinated Universal Time became the standard legal reference of time all over the world in 1972. UTC is determined from six primary atomic clocks that are coordinated by the International Bureau of Weights and Measures (BIPM) based in France. The numbers located at the bottom of Figure 2c-1 indicate how many hours each zone is earlier (negative sign) or later (positive sign) than the Coordinated Universal Time standard.

There are eleven time zones in Russia, from the second to the twelfth. There were much more technical problems than expected at first, but then the Soviet government resolution of March 1924 adopted standard time zones throughout the country. Russia started to use daylight saving time in 1981.

Daylight saving time is the convention of advancing clocks so that afternoons have more daylight and mornings have less. Typically clocks are adjusted forward one hour near the start of spring and are adjusted backward in fall. Modern DST was first proposed in 1907 by the English builder William Willett. Many countries have used it since then; details vary by location and change occasionally.

“Standardized time zones enabled the world astronomic community to unify the count of minutes and seconds at each observatory of the planet,” Smirnov said. He recalled that the World Astronomical Union initiated the holding of the International Year of Astronomy in 2009. UNESCO and the United Nations supported the project, he said.