Why are there different time zones?: Quick Facts

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The Information Architects of Encyclopaedia Britannica

Last updated

Nov. 1, 2026

Photos

World map showing standard time zones, with each zone shaded and labeled by its offset from Greenwich Mean Time. The International Date Line is marked with a bold, zigzagging line in the Pacific Ocean, and variations for half-hour and other non-standard offsets are indicated. Continents, major countries, and oceans are labeled for reference.

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