Unix Timestamp
Convert between Unix timestamps and human-readable dates
100% free. Runs entirely in your browser - your files and data never leave your device and nothing is uploaded to any server.
About this tool
A Unix timestamp represents a point in time as the number of seconds since January 1, 1970 (the "Unix epoch") - widely used in programming and databases because it's a simple, unambiguous number rather than a formatted date string. This tool converts between Unix timestamps and human-readable dates in either direction.
How to use this tool
- Pick a directionConvert a timestamp into a date, or a date into a timestamp. Both are on the page at once.
- Enter your valuePaste a timestamp such as 1704067200, or choose a date and time.
- Choose seconds or millisecondsUnix timestamps are normally seconds. JavaScript uses milliseconds, which is why a value can come out 1,000x wrong if the unit is set incorrectly.
- Set the timezoneResults are shown in your local time and in UTC, so you can see both without converting by hand.
- Read every formatISO 8601, local time, UTC and a human-readable relative time ("3 days ago") are all produced at once.
Key features
- Converts in both directions without switching modes.
- Shows local time and UTC side by side, which is where most timezone bugs are actually spotted.
- Handles both seconds and milliseconds explicitly rather than guessing.
- Gives ISO 8601 output, the format most APIs and databases expect.
- Shows relative time, so you can tell at a glance whether a timestamp is in the past or the future.
Common uses
- Developers debugging an API response that returns raw epoch values.
- Checking whether a token or cache entry has already expired.
- Reading timestamps out of a database export or a log file.
- Converting a date into a timestamp for a query parameter or a test fixture.
- Confirming that a scheduled job fired at the time you expected.
Tips for better results
- If your converted date lands in 1970, the value was almost certainly milliseconds interpreted as seconds. Switch the unit.
- Store timestamps in UTC and convert only for display. It removes an entire category of daylight-saving bugs.
- ISO 8601 is the safest format for passing dates between systems - it is unambiguous about both the timezone and the field order.
- A negative timestamp is valid and means a date before 1970.
Mistakes to avoid
- Mixing seconds and milliseconds. A JavaScript Date.now() value is 1,000x a standard Unix timestamp.
- Assuming a timestamp carries a timezone. It does not - it is always an instant in UTC, and the timezone only affects how you display it.
- Using a 32-bit integer for timestamps. Those overflow in January 2038, which is a real constraint in older systems.
- Comparing timestamps from different units without normalising them first.
Frequently asked questions
The number of seconds that have elapsed since 1 January 1970 at 00:00:00 UTC, known as the Unix epoch. It is a single number that represents an exact instant, which is why databases and APIs prefer it over formatted dates.
Paste the number into the timestamp field above and the date appears immediately in local time, UTC and ISO 8601 format. Make sure the seconds/milliseconds toggle matches your value.
Almost always a unit mismatch. Your value is in milliseconds but is being read as seconds, so it lands only a few hours after the epoch. Switch the toggle to milliseconds.
A standard Unix timestamp counts seconds, giving a 10-digit number today. JavaScript's Date.now() returns milliseconds, giving 13 digits. If your number has 13 digits, it is milliseconds.
No. It always represents an instant in UTC. Timezones only matter when you format it for display, which is why this tool shows both your local time and UTC.
An international standard for writing dates and times, such as 2026-01-01T00:00:00Z. It is unambiguous about field order and timezone, making it the safest format to exchange between systems.
Systems storing timestamps in a signed 32-bit integer overflow on 19 January 2038, wrapping to a negative number and appearing as 1901. Modern systems use 64-bit values, which pushes the limit far beyond any practical concern.
Yes. Negative values represent dates before 1 January 1970. Some older systems and libraries handle these poorly, so test if you rely on them.
The page shows it live and updates as you watch, so you can copy the current epoch value directly.
A single integer is compact, sorts correctly, is trivially comparable, and has no formatting or locale ambiguity. Formatted dates invite parsing bugs across systems.
No. All conversion happens in your browser using the built-in date functions. Nothing is uploaded.
Use the date-to-timestamp side of the tool. Pick your date and time, and the epoch value in both seconds and milliseconds is produced.
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