International Date Line: Quick Facts

Written and fact-checked by

The Information Architects of Encyclopaedia Britannica

Last updated

Oct. 9, 2026

Facts

Also Known As	Date Line

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.

See All Images →

Topics

calendar Standard Time leap year quarter days Dionysian period intercalation time zone 22 Questions About Time and Timekeeping Answered clock Gregorian calendar Our Days Are Numbered: 7 Crazy Facts About Calendars