Editing Standard time (section)

{{Short description|Synchronization of clocks within a geographical region}}
{{About|time synchronisation in a given area|the concept used in industrial engineering|Standard time (manufacturing)|the album by Laurence Juber|Standard Time (album){{!}}''Standard Time'' (album)}}
{{Distinguish|Time standard|Winter time (clock lag)}}
{{Use British English|date=March 2022}}

[[File:World Time Zones Map.png|thumb|right|Worldwide time zones at present]]

'''Standard time''' is the synchronization of clocks within a geographical region to a single time standard, rather than a [[local mean time]] standard. Generally, standard time agrees with the local mean time at some meridian that passes through the region, often near the centre of the region. Historically, standard time was established during the 19th century to aid [[weather forecasting]] and train travel. Applied globally in the 20th century, the geographical regions became [[time zone]]s. The standard time in each time zone has come to be defined as an [[UTC offset|offset from Universal Time]]. A further offset is applied for part of the year in regions with [[daylight saving time]].

The adoption of standard time, because of the inseparable correspondence between [[longitude]] and time, solidified the concept of halving the globe into the [[Eastern Hemisphere]] and the [[Western Hemisphere]], with one [[IERS Reference Meridian|Prime Meridian]] replacing the [[Prime meridian#History|various prime meridians]] that had previously been used.