ALL DEVELOPER TOOLS56
Time Zone Converter
Time Zone Converter — One Instant, Every Zone
Convert one moment into as many zones as you need, with the date, the UTC offset and the abbreviation for that exact instant.
About Time Zone Converter
Every scheduling mistake this page exists to prevent comes from one assumption: that a time zone has an offset. It does not. An offset belongs to a moment. New York is five hours behind UTC in January and four in July, Sydney runs the opposite way round, India sits five and a half hours ahead all year and Nepal five and three quarters. So nothing here adds or subtracts a stored number. Each row asks the browser's own copy of the IANA time zone database what the clock read at the exact instant you named, and prints the offset and the abbreviation that came back with it. The board carries the date as well as the time, because the date is the half people drop. Thursday evening in London is Friday morning in Tokyo, and a column of bare times hides the day; zones on a different calendar date are marked as such. Two readings of a clock face have no single answer, and both are reported rather than resolved quietly: the hour a spring forward deletes, and the hour a fall back runs twice. A Unix timestamp field drives the board in both directions, in seconds or milliseconds, chosen rather than guessed from the digits.
Questions
The time it gives me is an hour out.
Check the anchor zone first — the row marked anchor is the one your typed clock reading belongs to, and changing it keeps the reading and moves the instant. If that is right, the remaining cause is a stale zone database. Every offset here comes from your browser's own copy of the IANA rules, so a machine that has not had an OS update since a country last changed its clocks will be wrong by exactly one hour, and this page will faithfully repeat that. Nothing on the page can correct for it; updating the operating system can.
What happens if I pick a time daylight saving skipped?
It says so instead of quietly moving on. There is no 02:30 on the morning a zone springs forward — the clock goes straight from 02:00 to 03:00, so that reading never existed. The board still computes, using the offset in force before the jump, and a banner names the zone, the size of the jump and the reading the instant actually lands on. That is the same instant a calendar invite for the missing time would end up at, which is usually what you wanted to know. The half-hour jumps are detected too, not just the sixty-minute kind.
Why does it say my time happens twice?
Because it does. When a zone falls back, the hour before the change and the hour after read the same on a clock face, sixty minutes apart, at two different offsets. Nothing about the digits you typed distinguishes them, so the page shows both instants with their offsets and tells you it is using the earlier one. Most libraries pick one silently; that is fine until you are reconciling a log against a calendar and an hour of events appears to be in the wrong order. The banner gives both UTC instants so you can name the one you meant.
Why is my zone labelled GMT+5:30 instead of IST?
Because that is what the browser calls it, and it is passed through rather than dressed up. Only some zones have a customary letter abbreviation in the browser's English data; the rest get a GMT offset form. The abbreviations that do exist are not unique either — IST is claimed by India, Ireland and Israel, and CST by China, Cuba and the North American central zone — so they are shown as labels, never as identifiers. The IANA name in the small type under each city, and the UTC offset on the right, are the parts that unambiguously identify what you are looking at.
Can I convert a whole list of timestamps at once?
No. This page converts one instant into many zones, which is the meeting-planner shape; it is not a batch converter and there is no file input. If you have a column of timestamps, the Timestamp Converter handles them one at a time between Unix seconds, milliseconds, ISO 8601 and a human-readable line. What this page does add is the Copy button on the board, which gives you the whole table as plain text — every zone with its date, time, offset and abbreviation, plus the UTC instant — ready to paste into an invite or a ticket.
Is my file uploaded to a server?
No. Transmute processes everything locally in your browser using JavaScript and WebAssembly. Your files never leave your device — there is no server, no upload, no cloud processing.