Unix Timestamp Converter
Convert Unix timestamps to readable dates and back. Handles seconds, milliseconds and microseconds, ISO 8601, your timezone and ISO week numbers.
- Unix (seconds)
- Unix (milliseconds)
- ISO 8601
- UTC
- Your timezone
- RFC 2822
- Relative
- Day of week
- ISO week
- Day of year
Related tools
All Date & Time tools →This tool runs entirely in your browser. Nothing you enter is sent to our servers, so there is nothing for us to store or see.
About the Timestamp Converter
Convert a Unix timestamp into a readable date, or a date back into a timestamp. Paste either one and every representation appears at once: seconds, milliseconds, ISO 8601, UTC, RFC 2822, your own timezone, a relative description, the ISO week number and the day of the year.
The problem this tool really solves is units. JavaScript counts milliseconds since 1970; almost every other language, database and API counts seconds. The two are indistinguishable by eye — both are just a long number — and mixing them up puts your date in January 1970 or fifty thousand years into the future. The unit is detected from the magnitude and stated plainly above the results, and you can force a different one to confirm a suspicion. Microsecond timestamps, which Postgres and some tracing systems emit, are handled too.
The ISO week number is worth a mention because it is the field people most often compute wrongly. Week 1 is the week containing the first Thursday of the year, which means the 1st of January can legitimately fall in week 52 or 53 of the previous year. That is calculated correctly here, along with the week-year that goes with it.
How to use the Timestamp Converter
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Paste a timestamp or a date
Any Unix timestamp in seconds, milliseconds or microseconds, or a date like 2026-08-17 14:30 or a full ISO 8601 string. The Now button fills in the current moment.
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Check how it was read
The line under the field states which unit was detected. If it guessed wrong — which happens with dates near 1970 — pick the unit explicitly from the dropdown.
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Read the conversions
Every representation updates as you type, including the same moment rendered in your own timezone.
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Copy what you need
Each row has its own copy button, so you can take just the ISO string or just the epoch seconds.
Frequently asked questions
What is a Unix timestamp?
The number of seconds that have elapsed since 00:00:00 UTC on 1 January 1970, called the Unix epoch. It is a single number with no timezone attached, which is exactly why it is used for storing and transmitting moments in time — the ambiguity that causes date bugs simply is not there.
How do I tell seconds from milliseconds?
By length. A timestamp for any date near the present is 10 digits in seconds and 13 in milliseconds; 16 digits means microseconds. This tool detects the unit from the magnitude and tells you which one it used, and you can override it if the guess is wrong.
Why does my date show as 1970 or as some absurd future year?
Almost always a units mismatch. Feeding milliseconds to something expecting seconds lands you around the year 56000; feeding seconds to something expecting milliseconds lands you in January 1970. Switch the unit dropdown to the other option and the correct date usually appears.
What timezone are the results in?
The ISO 8601, UTC and RFC 2822 rows are always UTC, which is what a timestamp actually represents. The "Your timezone" row renders the same moment in whatever zone your device is set to, detected in your browser without any location lookup.
What is the year 2038 problem?
Systems that store Unix time in a signed 32-bit integer overflow on 19 January 2038 and wrap around to 1901. It affects older embedded systems and legacy C code; modern 64-bit timestamps push the limit roughly 292 billion years out. This tool uses JavaScript numbers and handles dates far past 2038.