العربية

Unix timestamp converter

Convert integer Unix timestamps and exact UTC date-times, and display the same instant in a selected IANA zone without guessing units.

An integer Unix value in the selected unit; seconds and milliseconds are never guessed. UTC must be YYYY-MM-DDTHH:mm:ssZ or include .SSS before Z. No ambiguous local time, leap second or input offset. Years 0001–9999. Whole-second output rejects lost milliseconds. IANA is for display only using your browser data; default UTC.

Digits 0–9, ٠–٩ and ۰–۹ are accepted. Oversized input is rejected without silent truncation.

Calculation stays in your browser without uploads or automatic storage. Operations are bounded and synchronous; there is no background job or Cancel button. Only page assets are loaded from the site.

How to use

Choose the direction and Unix unit first. Enter the number or UTC string and a display zone such as UTC or Asia/Riyadh. Calculate to see Unix, UTC with three millisecond digits, and the local display with its offset. Copy or download the report.

Try an example

Unix -1 millisecond is 1969-12-31T23:59:59.999Z; -1 second is 1969-12-31T23:59:59.000Z. Zero seconds displayed in Asia/Riyadh is 1970-01-01T03:00:00.000 with GMT+03:00.

Support & limits

Integers are checked with BigInt before Number, without unit guessing or precision loss. ISO accepts Z only, seconds 00–59, and exactly three fractional digits when present. Invalid dates, 24:00:00 and automatic month rollover are rejected. IANA only displays an already determined instant using the browser’s Intl database; ambiguous or nonexistent local DST times are not converted in reverse. A zone display outside the supported years is rejected. Unix here does not count leap seconds.

Common questions

Why do some UTC times reject whole-second output?

They contain nonzero milliseconds. Select milliseconds to preserve the instant; neither positive nor negative values are rounded or floored. The host device zone is never an implicit default.

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