Unix Timestamp Converter
This Unix timestamp converter turns epoch values in seconds, milliseconds or microseconds into ISO 8601, RFC 1123 and local time, converts dates back to epoch, and shows the live current Unix time.
Current Unix time
17850713622026-07-26T13:09:22.000Z
About Unix Timestamp Converter
Logs, tokens, database columns and API payloads all carry epoch integers, and the first thing you need is the human date behind one. Paste any epoch value and the converter detects its unit from the digit count - ten digits is seconds, thirteen is milliseconds, sixteen is microseconds - then shows the ISO 8601 form in UTC, the RFC 1123 form, the same instant in your own local time, and a relative description such as three hours ago. A second field runs the conversion the other way, from a date to epoch seconds and milliseconds.
Unix time counts seconds elapsed since 1970-01-01T00:00:00Z and deliberately ignores leap seconds, which is why it is unambiguous across time zones and why protocols reach for it. The classic failure is a unit mix-up: a millisecond value read as seconds lands tens of thousands of years in the future, and a seconds value read as milliseconds lands in January 1970. Both look like data corruption on a dashboard. ISO 8601, tightened for internet use by RFC 3339, and the RFC 1123 form used in HTTP Date headers are the two renderings you are most likely to need.
Everything runs in the browser using the platform's own date implementation, so no timestamp you paste is uploaded and the page needs no network round-trip. The detected unit is displayed alongside the result rather than applied silently, so you can see whether the heuristic guessed what you meant. A clock at the top of the page updates every second with the current epoch value and its ISO form, and each output row has a copy button. Local time comes from your operating system's time zone, not from a server's.
How to use it
- 1Read the Current Unix time card at the top if all you need is the epoch value for right now, and copy it in one click.
- 2Paste an epoch integer into the Unix timestamp field - seconds, milliseconds or microseconds, with no need to say which.
- 3Check the Detected unit row to confirm the value was read as you intended.
- 4Read the ISO 8601, RFC 1123, local time and relative rows, copying whichever form you need.
- 5To go the other way, type a date into the second field in any format the browser can parse, such as 2026-07-19T14:30:00Z, and read back Unix seconds and milliseconds.
Common use cases
- -Turning an epoch value from an application log into a date you can line up against an incident timeline.
- -Checking the exp claim of a token or an expiry field expressed as a bare epoch integer.
- -Converting a cut-off date into epoch seconds for a query parameter, a cron calculation or an API filter.
- -Diagnosing a timestamp that renders as 1970 or as a date far in the future, which almost always means a seconds and milliseconds mix-up.
- -Reading the current Unix time to fill in a scheduled job, a cache expiry or a test fixture.
Frequently asked questions
- How do I convert a Unix timestamp to a date?
- Normalise the value to seconds, then add that many seconds to 1970-01-01T00:00:00Z. In practice you paste the integer here: the unit is detected from its length and you get ISO 8601 in UTC, the RFC 1123 form, your local time and a relative description at once. Doing it by hand is where time-zone and sign mistakes creep in.
- How can I tell if a timestamp is in seconds or milliseconds?
- Count the digits. For any date in the current era, a seconds value has ten digits, milliseconds thirteen and microseconds sixteen. Anything around 1.7 billion is seconds; around 1.7 trillion is milliseconds. If a date renders in 1970 you passed seconds to a millisecond API, and if it renders tens of thousands of years out you did the reverse.
- What is the difference between ISO 8601 and RFC 1123 time formats?
- ISO 8601, tightened for internet protocols by RFC 3339, is the sortable 2026-07-19T14:30:00Z form used in APIs, logs and JSON. The RFC 1123 form, Sun, 19 Jul 2026 14:30:00 GMT, is the fixed-length English text HTTP requires in Date, Expires and Last-Modified headers. Same instant, different serialisation, and this converter shows both for any epoch value.
- What is the year 2038 problem?
- Systems that store Unix time in a signed 32-bit integer overflow on 19 January 2038, when the count passes 2,147,483,647, and wrap round to a negative value in 1901. Anything still using a 32-bit time_t, including some embedded devices and old database columns, needs a wider type before then. Modern platforms use 64-bit values, which push the limit beyond any practical horizon.