FreeTimeZoneConverterES (Español)

How it works

Data

Every place on the site is tied to an IANA time zone id, such as America/Chicago or Asia/Kolkata. The IANA time zone database is the public record of every region's UTC offset and daylight saving rules, past and scheduled, and it is built into every modern browser and operating system. The conversion runs in your browser using the built-in Intl date functions, so nothing you type is sent anywhere, and when a country changes its rules your browser's next update brings the change.

Converting a time

  1. The time you pick is a wall-clock time in the first place ("9:00 AM on March 20 in New York").
  2. That is turned into one exact instant using New York's offset on that date.
  3. The instant is shown as a wall-clock time in the second place, using that place's offset at that instant.

Because the offset is looked up for the exact date, the gap between two places is right even in the weeks when they are out of step. For example, the US moves its clocks forward on March 8, 2026 but the UK waits until March 29, so New York and London are 4 hours apart in between and 5 hours apart otherwise.

Times that don't exist or happen twice

When clocks spring forward, one hour of local time is skipped (in the US, 2:00 to 2:59 AM). If you pick a skipped time, we move it forward by the size of the jump: 2:30 AM becomes 3:30 AM daylight time. When clocks fall back, one hour happens twice; we use the first one. This matches how the JavaScript Temporal standard resolves these times by default. The hour-by-hour table shows 23 rows on a spring-forward day and 25 on a fall-back day.

Abbreviations

Abbreviations such as EST or CET are treated as the places that use them: EST means Eastern Time as kept in New York, which is EST (UTC−5) in winter and EDT (UTC−4) in summer. GMT and UTC are the exceptions: they are fixed at UTC+0 all year. Abbreviations that are shared between zones (CST, IST, AST, PST, BST, GST) are mapped to one meaning on purpose, and the converter shows the others when you type them. The full list is on the abbreviations page.

What "current time" means

The converter starts with the current time from your device clock and your device's time zone setting. Pages are generated ahead of time with an example time (9:00 AM on the day the page was built), which your browser replaces with the live time as soon as the page loads.

Testing

The conversion code has automated tests for the 2026 US clock changes (March 8 and November 1), the EU and UK changes (March 29 and October 25), the weeks in between when the US and Europe are out of step, southern-hemisphere zones (Sydney and Auckland, which switch the other way), places without daylight saving (Arizona, Hawaii, India, Japan), half-hour and 45-minute offsets (India, Newfoundland, Adelaide, Nepal), skipped and repeated times, and day changes across the date line.

We compared the 2026 switch instants with the published schedules on time.is: New York changes on March 8 at 07:00 UTC and November 1 at 06:00 UTC, London on March 29 and October 25 at 01:00 UTC, and Sydney on April 4 and October 3 at 16:00 UTC (April 5 and October 4 local time). All matched.

Limits

Results are only as current as the time zone data in your browser. Governments sometimes change daylight saving rules at short notice; keep your browser updated. Don't rely on this site where an error could cause harm, such as for aviation or legal deadlines. Spot an error? Email hello@freetimezoneconverter.com.