Greenwich Mean Time

British  

noun

1.  GMT.  mean solar time on the 0° meridian passing through Greenwich, England, measured from midnight: formerly a standard time in Britain and a basis for calculating times throughout most of the world, it has been replaced by an atomic timescale See universal time

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Greenwich Mean Time Scientific  

/ grĕn′ĭch /

1. See universal time

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Usage

The name Greenwich mean time is ambiguous, having been measured from mean midday in astronomy up to 1925, and is not used for scientific purposes. It is generally and incorrectly used in the sense of universal coordinated time , an atomic timescale available since 1972 from broadcast signals, in addition to the earliest sense of universal time , adopted internationally in 1928 as the name for GMT measured from midnight

Example Sentences

The IDF has even adopted Greenwich Mean Time, which the U.S. military uses.

From The Wall Street Journal • Mar. 11, 2026

UTC — Coordinated Universal Time, also known as Greenwich Mean Time, seven hours before it was planned to go out at 10:19 a.m.

From Seattle Times • Oct. 19, 2023

The United Kingdom, historically and emotionally tethered to the astronomical standard, enshrined in Greenwich Mean Time, has been reluctant to commit publicly.

From New York Times • Nov. 14, 2022

Greenwich Mean Time at the Royal Observatory in greater London is the global standard.

From Fox News • Jul. 28, 2020

He glanced at his watch, synchronized with Greenwich Mean Time by constantly updated radio signals.

From "Artemis Fowl" by Eoin Colfer