standard time

American  

noun

1. the civil time officially adopted for a country or region, usually the civil time of some specific meridian lying within the region. The standard time zones in the United States Atlantic time, Eastern time, Central time, Mountain time, Pacific time, Yukon time, Alaska-Hawaii time, and Bering time use the civil times of the 60th, 75th, 90th, 105th, 120th, 135th, 150th, and 165th meridians respectively, the difference of time between one zone and the next being exactly one hour.

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standard time British  

noun

1. the official local time of a region or country determined by the distance from Greenwich of a line of longitude passing through the area

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standard time Scientific  

1. The time in any of the 24 time zones into which the Earth's surface is divided, usually the mean time at the central meridian of the given zone. There are four standard time zones in the contiguous continental United States: Eastern, using the 75th meridian; Central, using the 90th meridian; Mountain, using the 105th meridian; and Pacific, using the 120th meridian. Alaska Standard Time, centered on the 135th meridian, is one hour behind Pacific time, and Hawaii Standard Time, centered on the 150th meridian, is one hour behind Alaska time.

2. See more at daylight-saving time time zone

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Etymology

Origin of standard time

An Americanism dating back to 1880–85

Example Sentences

See Examples For:

standard time

Areas that already do not observe daylight saving time — such as Arizona and Hawaii — would be able to stay on permanent standard time.

From Los Angeles Times ● Jul. 22, 2026

Permanent standard time would make San Francisco’s latest sunset of the year at 7:36 p.m.

From Los Angeles Times ● Jul. 22, 2026

About 56% of U.S. adults are in favor of it, while 42% prefer permanent standard time, which would provide more sunshine each morning, according to an AP-NORC poll conducted last year.

From MarketWatch ● Jul. 15, 2026

Instead, the group representing sleep doctors favors permanent standard time, saying it aligns best with a human’s circadian rhythm, meaning your body’s natural clock.

From MarketWatch ● Jul. 15, 2026

Sun time and standard time agree only four times a year, April 16, June 15, Sept.

From The Boy Mechanic: Volume 1 700 Things for Boys to Do by Popular Mechanics Co.