Countries can change time zones

The International Date Line is an imaginary line that passes through the Pacific from the North Pole to the South Pole. It marks the sectors on the globe in which the time zone immediate to the east is always one day earlier than that to the west.

Along with the Prime Meridian, the International Date Line was established during the International Meridian Conference in 1884 in Washington D.C.

The Greenwich meridian has served as the reference line for the Greenwich Mean Time, a prime basis of standard time throughout the world. Before this, there was no standard time and no way to measure when the day starts and ends.

Located 180 degrees away from the Greenwich meridian is the International Date Line.

The date line is important for travelers. A person leaving Manila on Jan. 10 in the morning will arrive in California still on Jan. 10 in the morning. The absence of a date line would make them think that they had lost or gained a day.

This happened to the crew of Ferdinand Magellan after the first circumnavigation of the globe in early 1500s. Antonio Pigafetta, who kept a daily record of the expedition, noticed after his return to Spain that he had gained one day.

Some countries had jumped across the dateline for administrative reasons—The Philippines in 1845, parts of Kiribati in 1995 and Samoa in 2011.

In 1994, Kiribati announced that it would move to the east of the International Date Line effective Jan. 1, 1995 so that the entire nation would be on the same side of the date line.

The date line curves around the islands of Kiribati in order that all the areas of the country would remain on the same day.

Are there international standards governing such move?  Can countries just independently decide to switch sides?

Countries can change time zones if they want to but this can be done only on their land and immediate territories. Open seas adopt the Coordinated Universal Time.

There is no international law governing time-zone shifts, according to Lou Angeli A. Ocampo, assistant professor at the Department of Geography, UP College of Social Sciences and Philosophy.

Ocampo says a country just has to inform the international community, especially cartographers, by publicizing the shift. Many countries do not follow the “prescribed” time zones. China is under one time zone even if it physically spans several zones; other countries adopt Daylight Saving Time. Ana Roa, Inquirer Research

Sources: rmg.co.uk, usno.navy.mil, education.nationalgeographic.com, Merriam Webster and Inquirer Archives