Editing Time zone (section)

=== Worldwide time zones ===
{{Redirect|World time|the global time standard|Universal Time}}
[[Italy|Italian]] mathematician [[Quirico Filopanti]] introduced the idea of a worldwide system of time zones in his book ''Miranda!'', published in 1858. He proposed 24 hourly time zones, which he called "longitudinal days", the first centred on the meridian of [[Rome]]. He also proposed a universal time to be used in astronomy and telegraphy. However, his book attracted no attention until long after his death.<ref>{{cite web |url=http://www.scienzagiovane.unibo.it/english/scientists/filopanti-1.html |title=Quirico Filopanti |website=scienzagiovane |publisher=Bologna University, Italy |archive-url=https://web.archive.org/web/20130117011106/http://www.scienzagiovane.unibo.it/english/scientists/filopanti-1.html |archive-date=January 17, 2013 |url-status=dead}}</ref><ref>{{cite web |title=Suggestions from... ...Gianluigi Parmeggiani, Osservatorio Astronomico di Bologna - The origin of time zones |url=http://www.iav.it/planetario/didastro/didastro/english.htm |website=Didastro |publisher=Istituti Aldini Valeriani e Sirani |archive-url=https://web.archive.org/web/20070824155341/http://www.iav.it/planetario/didastro/didastro/english.htm |archive-date=August 24, 2007 |url-status=dead}}</ref>

[[Scotland|Scottish]]-born [[Canada|Canadian]] Sir [[Sandford Fleming]] proposed a worldwide system of time zones in 1876 - see {{section link|Sandford Fleming|Inventor of worldwide standard time}}. The proposal divided the world into twenty-four time zones labeled A-Y (skipping J), each one covering 15 degrees of longitude. All clocks within each zone would be set to the same time as the others, but differed by one hour from those in the neighboring zones.<ref>{{Cite journal| issue = 1| pages = 345–366| last = Fleming| first = Sandford| title = Time-reckoning for the twentieth century| journal = Annual Report of the Board of Regents of the Smithsonian Institution| date = 1886| url = https://library.si.edu/digital-library/book/annualreportofbo18861smit| access-date = March 24, 2022| archive-date = October 5, 2022| archive-url = https://web.archive.org/web/20221005110429/https://library.si.edu/digital-library/book/annualreportofbo18861smit| url-status = live}} Reprinted in 1889: {{Internet Archive|timereckoningfor00flem|''Time-reckoning for the twentieth century''}}.</ref> He advocated his system at several international conferences, including the [[International Meridian Conference]], where it received some consideration. The system has not been directly adopted, but some maps divide the world into 24 time zones and assign letters to them, similarly to Fleming's system.<ref>{{cite news |last1=Stromberg |first1=Joseph |title=Sandford Fleming Sets the World's Clock |url=https://www.smithsonianmag.com/smithsonian-institution/sandford-fleming-sets-the-worlds-clock-389930/ |work=Smithsonian Magazine |date=November 18, 2011 |language=en |access-date=March 24, 2022 |archive-date=March 24, 2022 |archive-url=https://web.archive.org/web/20220324012426/https://www.smithsonianmag.com/smithsonian-institution/sandford-fleming-sets-the-worlds-clock-389930/ |url-status=live }}</ref>

[[File:World Time Zone Chart 1942.jpg|thumb|400px|World map of time zones in 1928]]

By about 1900, almost all inhabited places on Earth had adopted a standard time zone, but only some of them used an hourly offset from GMT. Many applied the time at a local astronomical observatory to an entire country, without any reference to GMT. It took many decades before all time zones were based on some standard offset from GMT or [[Coordinated Universal Time]] (UTC). By 1929, the majority of countries had adopted hourly time zones, though some countries such as [[Iran]], [[India]], [[Myanmar]] and parts of [[Australia]] had time zones with a 30-minute offset. [[Nepal]] was the last country to adopt a standard offset, shifting slightly to UTC+05:45 in 1986.<ref>{{Cite web|title=Time Zone & Clock Changes in Kathmandu, Nepal|url=https://www.timeanddate.com/time/zone/nepal/kathmandu|access-date=December 1, 2020|website=timeanddate.com|language=en|archive-date=January 22, 2021|archive-url=https://web.archive.org/web/20210122042454/https://www.timeanddate.com/time/zone/nepal/kathmandu|url-status=live}}</ref>

All nations currently use standard time zones for secular purposes, but not all of them apply the concept as originally conceived. Several countries and subdivisions use half-hour or quarter-hour deviations from standard time. Some countries, such as [[China]] and [[India]], use a single time zone even though the extent of their territory far exceeds the ideal 15° of longitude for one hour; other countries, such as [[Spain]] and [[Argentina]], use standard hour-based offsets, but not necessarily those that would be determined by their geographical location. The consequences, in some areas, can affect the lives of local citizens, and in extreme cases contribute to larger political issues, such as in the western reaches of China.<ref>{{Cite news|url=https://www.theatlantic.com/china/archive/2013/11/china-only-has-one-time-zone-and-thats-a-problem/281136/|title=China Only Has One Time Zone—and That's a Problem|last=Schiavenza|first=Matt|date=November 5, 2013|work=The Atlantic|access-date=August 22, 2018|language=en-US|archive-date=August 22, 2018|archive-url=https://web.archive.org/web/20180822145736/https://www.theatlantic.com/china/archive/2013/11/china-only-has-one-time-zone-and-thats-a-problem/281136/|url-status=live}}</ref> In [[Time in Russia|Russia, which has 11 time zones]], two time zones were removed in 2010<ref>{{cite web|url=https://www.timeanddate.com/news/time/russia-reduces-time-zones.html|title=Russia Reduces Number of Time Zones|date=March 23, 2010|work=TimeAndDate.com|access-date=May 31, 2020|archive-date=August 9, 2020|archive-url=https://web.archive.org/web/20200809084135/https://www.timeanddate.com/news/time/russia-reduces-time-zones.html|url-status=live}}</ref><ref>{{cite web|title=About Time: Huge country, nine time zones|date=March 22, 2011|access-date=February 12, 2019|format=Video|website=[[BBC]]|language=en|url=https://www.bbc.com/news/av/world-europe-12809230/about-time-huge-country-nine-time-zones|archive-date=February 13, 2019|archive-url=https://web.archive.org/web/20190213012708/https://www.bbc.com/news/av/world-europe-12809230/about-time-huge-country-nine-time-zones|url-status=live}}</ref> and reinstated in 2014.<ref>{{cite news |title=Russian clocks to retreat again in winter, 11 time zones return |url=https://uk.reuters.com/article/us-russia-time/russian-clocks-to-retreat-again-in-winter-11-time-zones-return-idUSKBN0F64YB20140701 |website=Reuters |date=July 2014 |access-date=October 25, 2020 |archive-date=October 28, 2020 |archive-url=https://web.archive.org/web/20201028205217/https://uk.reuters.com/article/us-russia-time/russian-clocks-to-retreat-again-in-winter-11-time-zones-return-idUSKBN0F64YB20140701 |url-status=dead }}</ref>