Time policy reference
Browse sourced timelines for countries with notable daylight saving time adoption, abolition, regional exceptions, permanent summer-time experiments, or unresolved reform debates.
29 timelines · 72 sourced events
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Wartime economics started the practice. Port Arthur, Ontario is cited as the first known place to run modern DST in 1908, and Germany introduced the first nationwide period on April 30, 1916, with the United Kingdom, France, Italy, and Belgium following the same year. The aim was fuel saving rather than convenience, which is why many countries dropped their clock changes as soon as each war ended.
The 1970s energy crisis brought seasonal time back. France resumed it in 1976, the Netherlands in 1977, and New Zealand reintroduced clock changes after a 1974 to 1975 trial. Europe later harmonized on the last Sunday in March to last Sunday in October pattern, and the United States settled on its current second Sunday in March to first Sunday in November season in 2007.
The recent movement runs the opposite way. Argentina stopped in 2009, Russia ended seasonal switching in 2011 and chose permanent standard time in 2014, Turkiye stayed on UTC+3 from 2016, Morocco fixed UTC+1 in 2018, Brazil abolished DST in 2019, and Iran and Mexico followed in 2022. Egypt went against the tide and reintroduced clock changes in April 2023 after eight years without them.
Every entry on a country page carries a year, one of four actions, and at least one source. Adopted marks a first observance or a return after a long gap. Abolished marks the end of seasonal changes. Modified covers schedule shifts, regional exceptions such as Chile's Magallanes Region moving to a fixed UTC-03:00 in 2017, and permanent-offset experiments. Voted-on flags reforms that passed a vote without becoming law, the 2019 European Parliament decision being the standing example.
Any timestamp recorded under a rule listed here, server logs, medical records, financial trades, birth certificates, needs the offset that was in force at that moment to convert correctly. The IANA time zone database encodes transitions from 1970 onward for every zone, which is why software usually handles recent history well. Dates before 1970, or inside short-lived arrangements like Russia's 2011 to 2014 permanent summer time or Cuba's 2004 to 2006 year-round DST, are exactly where a sourced timeline earns its keep.
Port Arthur, Ontario, now part of Thunder Bay in Canada, is cited as the first known place to run modern DST in 1908. Germany introduced the first nationwide period on April 30, 1916, during World War I, and the United Kingdom, France, Italy, and Belgium followed the same year.
No. Northern observers run their DST season roughly March to October or November: the United States uses the second Sunday in March to the first Sunday in November, and the EU the last Sunday in March to the last Sunday in October. Southern observers reverse it: Australian jurisdictions that observe DST run from the first Sunday in October to the first Sunday in April.
Not yet. The European Parliament backed ending seasonal clock changes in 2019, but the reform requires member-state agreement, so EU clocks still move on the last Sunday of March and the last Sunday of October.
Japan has not changed clocks since 1951, China stopped in 1991, South Korea after 1988, Russia in 2014, Turkiye in 2016, Brazil in 2019, and Mexico abolished it for most of the country in 2022. Iceland has stayed on GMT year-round since 1968, and South Africa last used DST in 1944.
A jurisdiction keeps its former DST offset all year instead of switching. Russia tried it from 2011 to 2014 before settling on permanent standard time, Turkiye has kept UTC+3 since 2016, and Morocco fixed UTC+1 in 2018 with adjustments around Ramadan. Ireland is the curiosity on paper: its law defines standard time as GMT+1, making winter the legal deviation.