Who / What
Greenwich Mean Time (GMT) is the local mean time at the Royal Observatory in Greenwich, London, counted from midnight. It serves as an alias for the UTC+00:00 time zone and is used in UK law as the basis for civil time. GMT cannot specify a particular time without context because it has historically been calculated in different ways.
Background & History
GMT originated from the local mean solar time of the Royal Observatory in Greenwich. Historically it has been calculated in various ways, including from noon and from midnight. The term has evolved to become one of the names for the UTC+00:00 time zone. In UK law, GMT is the legal foundation for the country's civil timekeeping.
Why Notable
GMT provides the reference point for the time zone UTC+00:00, which is used globally for timekeeping and navigation. It underpins civil time regulations in the United Kingdom and plays a crucial role in international time coordination. The observatory’s measurements of solar time established a standardized timescale that influenced timekeeping worldwide.
In the News
GMT remains the civil time standard in the United Kingdom and continues to be referenced in legal contexts and timekeeping practices. There are no recent changes or updates noted regarding its status or usage.
