100% local — your data never leaves your browser

Unix Timestamp to Date — Read a Log Line

Turn a Unix timestamp into a readable date: ISO 8601, UTC, your local time, seconds, milliseconds and how long ago it was, all at once.

Instant Private Zero cookies
Swap: Date → Timestamp

Timestamp input

Date output

What this tool does

A number in, six readings of the same instant out.

1780000000
ISO 8601 (UTC): 2026-05-28T20:26:40.000Z
UTC: Thu, 28 May 2026 20:26:40 GMT
Local: Thu May 28 2026 20:26:40 GMT+0000
Unix seconds: 1780000000
Unix milliseconds: 1780000000000
Relative: 4 months ago

The ISO line is the one to paste into a ticket or a query; the UTC line is the one to read out loud; the relative line answers the question you probably had — how long ago that was.

The same number, under its other names

Unix time, epoch time, POSIX time, Linux time: four names for one count — the seconds elapsed since 1 January 1970 at 00:00 UTC. Nothing distinguishes them, and looking up one rarely leads to the other.

Your stack renames it again. It is a long in Java and a BIGINT in a SQL column, a time_t in C, and what Date.now() hands back in JavaScript — that one in milliseconds. A timestamp read out of a log, a database or an API payload is this number, whichever word sat next to it.

What comes back is a datetime: a calendar date and a clock time, in the six forms above.

Seconds or milliseconds, decided by size

Thirteen digits and more are milliseconds, twelve and fewer are seconds. The boundary sits at a thousand billion: as seconds that would be the year 33658, as milliseconds it is September 2001, so no timestamp you are likely to hold is anywhere near it.

The one unit that can fool it is microseconds, which some databases and tracing tools emit: sixteen digits read as milliseconds put you in the year 58375. A date that absurd is the tell — divide by a thousand and convert again.

Where the reading lands

  • Before 1970. A negative number counts backwards from the epoch: -1000000000 is 24 April 1938.
  • Far from 1970. A date can hold about 285 000 years either side; past that you get Timestamp out of range rather than a date that means nothing.
  • In your timezone, for one line only. Local follows your browser, daylight saving included. The rest of the output is UTC or a plain count, so it says the same thing on every machine.
  • Relative to the moment you pressed. 4 months ago is computed against your clock now, not against a fixed point — convert the same number tomorrow and the wording moves.

Private by design

Everything runs locally in your browser with JavaScript. Your data is never uploaded, which makes the tool safe for sensitive content, and it keeps working offline.

Frequently asked questions

Seconds or milliseconds?
Both: twelve digits or fewer are read as seconds, thirteen and more as milliseconds. The line is at a thousand billion, which in seconds would be the year 33658 and in milliseconds is September 2001 — no real timestamp is near it in either unit. If your number is in microseconds, divide it by a thousand first: sixteen digits read as milliseconds land you in the year 58375, which is the tell.
What is the “Local” line?
The same instant written in your browser’s timezone, daylight saving included. It is the only line on the page that depends on where you are — everything else is UTC or a count. If you are checking a log entry against what a colleague sees, compare the ISO line, not this one.
Do timestamps before 1970 work?
Yes. A negative number counts backwards from the epoch: `-1000000000` is April 1938. Very large numbers stop working at the edge of what a date can hold — about 285 000 years either side of 1970 — and you get “Timestamp out of range” instead of a nonsense date.

Related converters