50 Fun Facts About Daylight Saving Time

Which two-word mnemonic tells you which way to move the clocks?

Clocks jump ahead an hour in spring and drop back in autumn; the phrase works only in countries that call autumn 'fall'.

Grammatically, which is the standard form of the term?

'Saving' is a participle describing the time, but the plural 'savings' is so common that many editors accept it.

Which countries were the first to adopt daylight saving nationally, on 30 April 1916?

The aim was to conserve coal during the war; Britain followed on 21 May the same year.

Which cities are recorded as the first in the world to enact daylight saving time, in 1908?

The two towns later merged into Thunder Bay; the idea reached national level in Europe eight years later.

Franklin is often credited with daylight saving. What did his satirical 1784 Journal de Paris letter actually propose?

He never suggested touching the clocks; the essay was a joke about Parisians sleeping through the morning sun.

What was the day job of George Hudson, the New Zealander who proposed a two-hour clock shift in 1895?

His shift work left him daylight hours for insect collecting, and he wanted more of them; he read his paper to the Wellington Philosophical Society.

British builder William Willett got the idea for daylight saving while doing what?

His 1907 pamphlet was called The Waste of Daylight; he proposed advancing clocks 80 minutes in four 20-minute steps.

How much did William Willett originally propose advancing the clocks each spring?

He died of influenza in 1915, a year before Britain finally adopted the change; a sundial in Petts Wood set permanently to summer time commemorates him.

Which rock frontman is William Willett's great-great-grandson?

Coldplay's 'Clocks' is presumably a coincidence.

The United States first adopted daylight saving time in which year?

The Standard Time Act also confirmed the time zones; Congress repealed DST after the war, over President Wilson's veto.

What did Franklin D. Roosevelt call the year-round daylight saving he instituted in February 1942?

It ran until September 1945; the zones were literally called Eastern War Time, Central War Time and so on.

Which 1966 US law first standardised the start and end dates of daylight saving across the country?

Before it, states and even towns picked their own dates; states may still opt out entirely, which Arizona and Hawaii did.

What happened to public support for year-round daylight saving over the winter of the 1974 US trial?

Dark winter mornings, and reports of children hit by cars on the way to school, ended the experiment early in October 1974.

Which US law, effective 2007, extended daylight saving to run from March to November?

It set DST from the second Sunday of March to the first Sunday of November: 34 weeks, about 65 percent of the year, so 'standard' time is the minority.

For roughly what share of the year is the United States on daylight saving time?

That is 34 weeks or 238 days; clocks change at 2:00 a.m. local time to minimise disruption.

Which two US states do not observe daylight saving time?

Puerto Rico, Guam, American Samoa, the Northern Marianas and the US Virgin Islands also skip it.

Which territory inside Arizona does observe daylight saving time?

The Hopi Reservation, entirely surrounded by the Navajo Nation, does not - creating a doughnut of clocks within a doughnut.

Why does Arizona stay on standard time all year?

The legislature opted out in March 1968; from March to November most of Arizona shares California's clock time.

Which US state did not observe daylight saving statewide until April 2006?

Indiana straddles the Eastern and Central zones; several counties near Cincinnati and Louisville had quietly observed DST anyway.

How did the Sunshine Protection Act, making daylight saving permanent, pass the Senate in 2022?

Sponsored by Florida's Marco Rubio, it then stalled in the House of Representatives.

As of 2023, roughly what proportion of the world's countries use daylight saving time?

They are concentrated in Europe and North America; near the Equator the day barely changes length, so shifting the clock gains nothing.

Since 1996, every EU country changes clocks on the same dates. When?

And at the same instant - 01:00 UTC - so the whole bloc jumps together.

A 2018 EU public consultation on scrapping the clock change drew how many responses?

Most were German and most wanted it gone; the European Parliament voted to abolish it from 2021 but the Council of Ministers never signed off.

What happened to the European Parliament's March 2019 vote to end seasonal clock changes?

Member states could not agree on whether to stay on summer or winter time, and the file has sat unopened ever since.

Which of these European countries keeps the same clock all year, never springing forward?

Belarus, Turkey and Russia are the other holdouts; Iceland sits on GMT all year despite being far enough west for UTC-1.

What did Russia do in 2011, then reverse in 2014?

Under President Medvedev the clocks went forward and never came back; in October 2014 they moved back an hour and stayed there.

Britain went two hours ahead of GMT during the summers of 1941 to 1945. What was this called?

Britain then tried year-round GMT+1 from 1968 to 1971 as 'British Standard Time' and abandoned it.

Which Australian states do NOT observe daylight saving?

Queenslanders voted it down 54.5 to 45.5 in a 1992 referendum after a three-year trial.

In the Southern Hemisphere, when does daylight saving run in the states of Australia that use it?

Summer is at the other end of the calendar, so Australians spring forward while Europeans fall back.

Lord Howe Island, off Australia, is unusual for a daylight saving shift of how much?

Its clocks go from UTC+10:30 to UTC+11, making it one of the very few places with a half-hour change.

Which country observes daylight saving every month except one, pausing it for Ramadan?

Since 2019 Morocco has treated GMT+1 as its standard time and dropped back an hour during the fasting month.

Which country switched to permanent daylight saving time in 2016 rather than changing clocks?

Turkey stayed on UTC+3 year-round; Russia had tried the same thing from 2011 to 2014 and given up.

Which country abolished daylight saving nationwide in 2022, apart from some border areas?

Sonora had already dropped it in 1998; Brazil ended DST in 2019 and Samoa in 2021.

Which South American country used daylight saving on and off from 1931 until ending it in 2019?

Its four separate DST eras were 1931-33, 1949-53, 1963-68 and 1985-2019.

Studies on the spring clock change report what jump in hospital heart attacks?

Traffic accidents also rise in the sleep-deprived days after the change, one of the main arguments against switching at all.

Which interests have historically lobbied FOR daylight saving time?

Farmers and evening-entertainment businesses have opposed it; the popular idea that DST was invented for farmers is backwards.

Why is daylight saving of little use near the Equator?

That is why almost no African or South-East Asian country bothers with it.

Which US president signed permanent daylight saving time into law in January 1974?

The energy-crisis experiment was meant to last two years and was cut short after one dark winter.

Which South Pole research stations run on New Zealand time, daylight saving included?

Their supply flights leave from Christchurch, so they simply keep Christchurch's clock.

At what local time do US clocks change on daylight saving days?

Authorities pick the small hours to minimise disruption; in spring 2:00 becomes 3:00 and in autumn 2:00 happens twice.

Britain first put its clocks forward in May 1916 under which piece of legislation?

Clocks now go forward at 01:00 GMT on the last Sunday of March and back at 02:00 BST on the last Sunday of October.

How many time zones does Russia span, all kept on standard time year-round since 2014?

They run from UTC+2 in Kaliningrad to UTC+12 in Kamchatka.

Which Antarctic research station shifts its clocks two hours at once, between GMT and CEST?

Since 2016 the Norwegian base has jumped straight between the two, an exception to the usual one-hour change.

Which lobby pushed the 2005 US extension so that Halloween would fall within daylight saving?

The Uniform Time Act's six-month period grew to seven months in 1986 and eight in 2005.

At what UTC instant do all European Union countries change their clocks together?

That keeps the gaps between European zones constant, unlike North America where each zone changes at its own 2 a.m.

How does Ireland's clock arrangement differ from most countries that observe daylight saving?

Irish Standard Time is UTC+1 in summer; in winter the country moves to an offset with the same name and time as Britain's GMT.

A 2017 meta-analysis of 44 studies found daylight saving cuts electricity use by roughly how much?

An early goal was reducing evening use of incandescent lighting; a 2025 study warned air conditioning may reverse the saving.

One estimate put the daylight-saving effect's cost to US stock exchanges in 2000 at how much?

Other researchers disputed the methodology, though the original authors defended their findings.

Which holy day does Israel deliberately end daylight saving before?

Religious Jews also prefer a shorter DST because it delays scheduled morning prayers into working hours.

What is IANA's catalogue of historical and predicted clock shifts, used by most Unix systems, called?

North America's 2007 rule change caused a 'year 2007 problem' that forced upgrades to email and calendar software.