Time zone converter.

The browser's own copy of the IANA time zone database, through the Intl API: the same tables your operating system uses for the clock, with every daylight saving rule past and future that it knows. The page carries no table of its own and makes no request.

Yes. The offset is worked out for the instant you enter, not for today, so a meeting in March is placed under the rule in force in March. The short name under the result says which rule applied: EST or EDT, GMT or BST.

A time that doesn't exist, 2:30 on the night clocks spring forward, is moved an hour ahead, which is what a wall clock would have shown. A time that happens twice, on the night they fall back, takes the first of the two.

A city is clearer than an abbreviation: CST is Central Standard Time in Chicago and China Standard Time in Shanghai. The IANA id in brackets is the exact zone; the list has fifty, and your own zone is added at the top.

The page opens on your zone and the current minute. Change the date and time, pick the zone it is in and the zone to read it in; the result shows the day shift (+1 day) when the calendar date differs.

Under the result, the same instant is listed in nine common zones with their offsets, so a call can be checked for everyone at once.

No. The conversion is done by the Intl API in your browser; the page makes no request with the time you enter.

No. The Time zone converter is free and opens without a sign-in, an account or an install.

The Time zone converter keeps nothing on a server; only the invoice generator saves its draft, in this browser's localStorage on your device. Nothing else is saved, and nothing is sent to shadcn.io.

A list of 51 zones grouped by region and named by city, with your own zone added at the top when it isn't in the list. The IANA id is shown next to each name.

The Swap button exchanges the two zones and keeps the same instant, so the time shown is the one you just read.

Use the Now button to put the current minute in the time field, in the zone you are converting from.

Closest to the Time zone converter: Unix timestamp converter, Age calculator, Calculator, Cron expression parser. Each opens on its own page, free and in the browser.

The Time zone converter is one of 20 in its group. The group's page, /tools/math, lists them all.

The tool is free. Its interface is built from shadcn.io's own components (Button, Input, Slider and the rest of the registry under /ui), which come in React, Vue, Svelte and Solid. Pro adds the blocks and templates for the product around it.