Spring forward, fall back: the mnemonic and its limits
It tells you the direction and nothing else — not the date, not whether your country does it, and not which way round it is south of the equator.
The short answer
In spring, clocks go forward one hour. In autumn, they go back one hour.
Forward means you lose an hour — 2am becomes 3am, and the night is shorter. Back means you gain one — 2am becomes 1am, and that hour happens twice.
What it gets right
The direction, which is the thing people actually forget. And a useful physical association: in spring you move the clock forward into lighter evenings; in autumn you set it back toward darker ones.
A second mnemonic that helps with the consequence rather than the direction: spring forward, lose an hour of sleep; fall back, gain one.
Limit one: it does not tell you the date
"Spring" is three months long. The actual dates are set by law and differ by region:
| Region | Forward | Back |
|---|---|---|
| United States | 2026-03-08 | 2026-11-01 |
| UK & EU | 2026-03-29 | 2026-10-25 |
Three weeks separate the US and EU spring changes, and about a week separates their autumn ones. The mnemonic gives no hint of that, and that gap is where recurring meetings break.
Limit two: it is backwards in the southern hemisphere
Australia, New Zealand, Chile and southern Africa's observers have their summer during the northern winter. Their clocks go forward in October and back in April.
So "spring forward" is still literally true — their spring is in October — but if you are thinking in northern-hemisphere months, it is exactly inverted. In 2026 the Australian states that observe it went back on 2026-04-04 and forward on 2026-10-03.
This is why the London↔Sydney gap swings by two hours across the year, between 11 hours ahead and 9 hours ahead.
Limit three: most of the world does not do it at all
The mnemonic quietly implies universality. It is not. Most of Asia, most of Africa, most of South America, and within the US, Arizona and Hawaii, never change their clocks.
If you deal with someone in a non-observing country, your clocks moved and theirs did not — so the entire adjustment, and the entire responsibility for noticing it, is yours.
The practical version
If you only remember one thing, remember the consequence rather than the mnemonic: twice a year, any arrangement you have with another country can silently move by an hour. Mid-March and late October are the moments to check.
And schedule against cities rather than offsets, so the database does the remembering for you.
Related: Daylight saving time explained · The clock change: what happens at 2am
Timezone: World Clock Widget
A world clock, converter and live day/night map for iPhone — 325 cities, offline, no account.
Figures on this page are computed from the IANA time zone database. Last generated 2026-08-18.