time zone

American  

noun

1. one of the 24 regions or divisions of the globe approximately coinciding with meridians at successive hours from the observatory at Greenwich, England.

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time zone British  

noun

1. a region throughout which the same standard time is used. There are 24 time zones in the world, demarcated approximately by meridians at 15° intervals, an hour apart See also zonetime

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time zone Scientific  

1. Any of the 24 divisions of the Earth's surface used to determine the local time for any given locality. Each zone is roughly 15° of longitude in width, with local variations for economic and political convenience. Local time is one hour ahead for each time zone as one travels east and one hour behind for each time zone as one travels west. The International Meridian Conference in 1884 established the prime meridian as the starting point for the 24 zones.

2. See more at International Date Line standard time

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Etymology

Origin of time zone

First recorded in 1880–85

Example Sentences

Coordinating time zone is only one tiny piece of the puzzle to pull this event off.

From Salon • Mar. 21, 2026

Not since Jan. 29 had it won outside of L.A., and only once this season had it won outside of the Pacific time zone.

From Los Angeles Times • Mar. 12, 2026

The note gave a deadline for payment of 17:00 on Thursday, he said, without specifying which time zone, and had a second deadline for Monday.

From BBC • Feb. 9, 2026

The family's renewed call came after the FBI disclosed that a first deadline of 5 pm on Thursday was made in a ransom letter, without providing a time zone.

From Barron's • Feb. 6, 2026

We always wait to watch new episodes together, even if I’m on an entirely different continent in another time zone and need to Skype them.

From "Five Feet Apart" by Rachael Lippincott