Daylight Saving Time

The Clock-Shift Animation

Next Transition Dates

Regions That Never Change Their Clocks

Most of the world keeps a fixed offset year round — daylight saving is mainly a North American, European, and southern-hemisphere practice.

US & EU DST Schedule (Upcoming Years)

Need to convert a fixed reference time? Use the UTC Converter — UTC never observes DST.

The Transition-Date Formula

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How to Use the Daylight Saving Time Tool

1. Pick Spring Forward or Fall Back to set the direction; the page gradient and the clock face flip between the green spring and amber autumn themes.
2. Watch the hour hand sweep from 2 o'clock to 3 (spring) or back to 1 (fall), with the lost or gained hour shaded on the dial.
3. Read the Next Transition Dates cards for the exact upcoming US and EU change dates and how many days away each one is.
4. Check the non-observing regions list to confirm whether your country changes its clocks at all (India, Japan, and Arizona, for example, never do).
5. Use the multi-year schedule table and the formula card to plan ahead, and remember UTC never shifts — store reference times there.

A History of Springing Forward

In 2026, a parent setting a child's bedtime, an airline crew scheduler rebuilding rosters, and a backend engineer bracing for the one night a year a local timestamp occurs twice all confront the same twice-yearly disruption: daylight saving time. This tool makes the abstract concrete with a clock that physically springs forward or falls back, visualising the hour you lose in spring and gain in autumn, alongside the exact next transition dates for the United States and the European Union and a clear list of which regions observe the change at all.

Daylight saving time is the practice of advancing clocks during the lighter months so that evening daylight lasts longer, then setting them back in autumn. The idea is usually credited to a 1784 satirical essay by Benjamin Franklin and to a serious 1895 proposal by New Zealand entomologist George Hudson, but the first national adoption came in 1916 when the German Empire moved clocks forward to save coal during the First World War. Britain, the United States, and others followed within two years.

In the United States, the modern schedule is set by the Energy Policy Act of 2005, which since 2007 has started daylight saving on the second Sunday of March (clocks spring forward from 2:00 AM to 3:00 AM) and ended it on the first Sunday of November (clocks fall back from 2:00 AM to 1:00 AM). The Uniform Time Act of 1966 first standardised the practice federally, while Arizona and Hawaii opt out entirely, as the law permits. The Sunshine Protection Act, which would make DST permanent, has passed the US Senate but not the House as of 2026.

The European Union coordinates its clock changes under Directive 2000/84/EC, moving on the last Sunday of March and the last Sunday of October, with the shift pinned to 01:00 UTC so that all member states change at the same instant rather than the same local time. A 2018 EU public consultation drew 4.6 million responses, 84 percent favouring abolition, and the European Parliament voted in 2019 to end mandatory changes, but the reform has stalled without agreement on whether to keep permanent summer or winter time.

The spring-forward transition deletes an hour: at 2:00 AM the clock jumps to 3:00 AM, so 2:30 AM simply does not exist that night, and people sleep one hour less. The autumn fall-back transition repeats an hour: at 2:00 AM the clock returns to 1:00 AM, so the 1:00-to-2:00 AM hour happens twice. This is the source of real engineering pain, because a naive local timestamp like 01:30 is ambiguous on fall-back night, which is precisely why servers store time in UTC, where no hour is ever skipped or repeated.

Time-zone identifiers and their daylight-saving rules live in the IANA Time Zone Database (the tz database, zoneinfo, or Olson database, after founder Arthur David Olson), the canonical source read by Linux, macOS, Java, Python, and the browser's Intl.DateTimeFormat API. The database encodes not just current rules but the full history of every region's transitions, which is why software can correctly render a timestamp from a year when the rules were different. The non-observing list this tool shows — India, Japan, China, most of Africa, Arizona, Hawaii — comes straight from those rules.

The health and economic effects keep DST politically alive. Studies in journals including the American Journal of Cardiology and Current Biology associate the spring transition with a short-term rise in heart attacks, traffic accidents, and workplace injuries from the lost hour of sleep, and the American Academy of Sleep Medicine's 2020 position statement advocates abolishing the switch in favour of permanent standard time. Whether your region springs forward, falls back, or never moves, this calculator shows the next transition so you can prepare your sleep, your schedules, and your code before the clocks change.