Editing Daylight saving time (section)

== Overview ==
As of 2023, around 34 percent of the world's countries use DST.<ref>{{cite web | last=Haines | first=Julia | title=Which Countries Observe Daylight Saving Time? | website=US News & World Report | date=November 6, 2023 | url=https://www.usnews.com/news/best-countries/articles/2023-11-06/which-countries-observe-daylight-saving-time | access-date=November 4, 2024}}</ref> Some countries observe it only in some regions. In Canada, all of [[Yukon Time Zone|Yukon]], most of [[Time in Saskatchewan|Saskatchewan]], and parts of [[Nunavut]], [[Ontario]], [[British Columbia]] and [[Quebec]] do not change clocks, and use permanent DST. It is observed by four Australian states and one territory. [[Daylight saving time in the United States|In the United States]], it is observed by all states except Hawaii and Arizona (within the latter, however, the [[Navajo Nation]] does observe it).<ref>{{cite web|url=https://www.timeanddate.com/time/us/arizona-no-dst.html |title=No DST in Most of Arizona }}</ref>

Historically, several ancient societies adopted seasonal changes to their timekeeping to make better use of daylight; [[Roman timekeeping]] even included changes to [[water clock]]s to accommodate this.  However, these were changes to the time divisions of the day rather than setting the whole clock forward. In a satirical letter to the editor of the ''[[Journal de Paris]]'' in 1784, [[Benjamin Franklin]] suggested that if [[Parisians]] could only wake up earlier in the summer they would economize on candle and oil usage, but he did not propose changing the clocks.<ref>{{Cite web |date=7 July 2017 |title=Did Ben Franklin Invent Daylight Saving Time? |url=https://www.fi.edu/benjamin-franklin/daylight-savings-time |url-status=live |archive-url=https://web.archive.org/web/20210601024205/https://www.fi.edu/benjamin-franklin/daylight-savings-time |archive-date=1 June 2021 |access-date=5 August 2021 |website=The Franklin Institute |language=en}}</ref><ref>{{Cite web |title=Full text – Benjamin Franklin – The Journal of Paris, 1784 |url=http://www.webexhibits.org/daylightsaving/franklin3.html |url-status=live |archive-url=https://web.archive.org/web/20171115130303/http://www.webexhibits.org/daylightsaving/franklin3.html |archive-date=15 November 2017 |access-date=5 August 2021 |website=www.webexhibits.org}}</ref> In 1895, [[New Zealand]] entomologist and astronomer [[George Hudson (entomologist)|George Hudson]] made the first realistic proposal to change clocks by two hours every spring to the [[Wellington Philosophical Society]], but this was not implemented until 1928 and in another form.<ref name="DNZB-Hudson" /> In 1907, [[William Willett]] proposed the adoption of [[British Summer Time]] as a way to save energy; although seriously considered by Parliament, it was not implemented until 1916.<ref name="Ogle" />

The first implementation of DST was by [[Port Arthur, Ontario|Port Arthur]] (today merged into [[Thunder Bay]]), in Ontario, Canada, in 1908, but only locally, not nationally.<ref name="Northern Ontario Travel">{{Cite news |date=8 March 2018 |title=Time to change your clocks – but why? |url=https://www.northernontario.travel/thunder-bay/the-thunder-bay-connection-to-daylight-savings-time |url-status=live |archive-url=https://web.archive.org/web/20181010011523/https://www.northernontario.travel/thunder-bay/the-thunder-bay-connection-to-daylight-savings-time |archive-date=10 October 2018 |access-date=9 October 2018 |work=Northern Ontario Travel |language=en}}</ref><ref name="Daylight Saving Time">{{citation |title=Daylight Saving Time |url=https://www.timeanddate.com/time/dst/ |access-date=8 October 2018 |archive-url=https://web.archive.org/web/20181009153519/https://www.timeanddate.com/time/dst/ |archive-date=9 October 2018 |url-status=live}}</ref> The first nation-wide implementations were by the [[German Empire|German]] and [[Austria-Hungary|Austro-Hungarian]] Empires, both starting on 30 April 1916. Since then, [[daylight saving time by country|many countries]] have adopted DST at various times, particularly since the [[1970s energy crisis]].{{Citation needed|date=April 2025}}