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Unix Timestamp Converter

Translate epoch seconds and millis to dates both ways.

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Frequently asked questions

What is a Unix timestamp counting from?

Seconds elapsed since midnight UTC on 1 January 1970, known as the epoch. Because it is a plain number with no timezone attached, it is unambiguous — which is exactly why systems store and exchange time this way.

Is my timestamp in seconds or milliseconds?

Count the digits. Ten digits is seconds (the Unix convention); thirteen is milliseconds (the JavaScript convention). Feeding milliseconds into a seconds-based parser lands you tens of thousands of years in the future — a very common bug.

What is the year 2038 problem?

A signed 32-bit timestamp overflows on 19 January 2038, wrapping to a negative number and therefore to 1901. Modern systems use 64-bit values, but embedded devices and old database columns can still be affected.

Pro tips

  • Count the digits before assuming a unit: ten is seconds, thirteen is milliseconds. It is the fastest way to catch the mistake.
  • A date landing in 1970 almost always means milliseconds were read as seconds; one in the far future means the reverse.
  • Store and transmit timestamps in UTC and convert only for display — converting early is what produces off-by-an-hour bugs twice a year.
  • Use ISO 8601 in anything a human will read. Epoch values are efficient and unreadable, and a log nobody can scan costs more than the bytes saved.
  • Watch for dates computed far into the future on 32-bit systems, where 2038 is a live constraint rather than a curiosity.

About Unix Timestamp Converter

Works in both directions, which is exactly what you want when a log line hands you 1735689600 and the bug report hands you a date. Epoch values are also the usual culprit when a record turns up dated 1970.

Translate a Unix epoch timestamp into a readable date and time — in both UTC and your local zone — and convert dates back to epoch seconds or milliseconds. All conversion is computed locally.

Convert between Unix epoch time, ISO 8601 and human-readable dates in both directions, including relative time like '3 hours ago'. It is an everyday helper for working with logs, API responses, database timestamps and debugging time-zone issues.

Paste an epoch value to read it as a date, or pick a date to get its timestamp. Both seconds and milliseconds are shown, since APIs disagree about which one they mean by 'timestamp'.

Unix time counts seconds since midnight UTC on 1 January 1970, which makes it compact, timezone-free and naturally sortable — the reasons it appears throughout logs, tokens, databases and APIs. The recurring bug is units: the convention is seconds, but JavaScript, Java and plenty of APIs use milliseconds, and mixing them does not error. It silently produces a date in 1970 or one roughly fifty thousand years out. A quick check is digit count — a current timestamp is ten digits in seconds and thirteen in milliseconds.

Two further properties are worth knowing. A signed 32-bit timestamp overflows on 19 January 2038 and wraps to 1901, which is not a distant problem: any system computing dates decades ahead — a mortgage schedule, a long-dated certificate, a retention policy — can reach it today on 32-bit hardware. And Unix time deliberately ignores leap seconds, so it is not a true count of elapsed seconds. For application work that is exactly what you want; for measuring precise intervals across a leap second it is a documented limitation rather than a bug.

Common use cases

  • Reading a timestamp from a log line or database row
  • Checking when a token or cache entry actually expires
  • Converting an API's numeric date into something human-readable
How it comparesepochconverter.com is the long-standing reference and covers more exotic epoch formats. The everyday need is bidirectional conversion with both seconds and milliseconds visible at once, which is what removes the guess about which unit an API meant.