How to Convert a Unix Timestamp
A Unix timestamp is simply the number of seconds since the first of January 1970. It is how nearly every database, log file and API stores a moment in time, because a single integer has no timezone, no locale and no ambiguity about whether 03/04 means March or April. The cost is that it is unreadable, which is what this page fixes — in both directions, with the seconds-versus-milliseconds question answered automatically.
Paste a timestamp or a date
Either direction works. A plain number is read as a timestamp, anything else as a date.
Let it detect the unit
Ten digits is seconds, thirteen is milliseconds. You can override it if you know better.
Copy the format you need
ISO for APIs, Unix for storage, local time for humans - one click copies any of them.
Seconds or Milliseconds — the Bug Everyone Hits
This is the single most common timestamp mistake, and it is easy to miss because nothing errors. Most languages store Unix time in seconds. JavaScript uses milliseconds. Feed a seconds value into a JavaScript date and you get a moment in January 1970. Feed a milliseconds value into something expecting seconds and you land roughly fifty thousand years in the future.
The tell is the digit count. A current timestamp in seconds is ten digits; in milliseconds it is thirteen. That will hold until the year 2286, so it is a reliable rule for anything you will realistically encounter, and it is what the detection here uses.
The other thing worth knowing is that a Unix timestamp has no timezone. It is an absolute instant, the same number everywhere on Earth. The timezone appears only when you format it for display — which is exactly why storing timestamps rather than formatted strings avoids an entire category of bug. The table above shows the same instant rendered in ten places.
Common Situations This Tool Solves
Reading timestamps in a log file
Logs are full of raw epoch numbers. Pasting one here tells you immediately when the event happened, and how long ago.
Checking an API response
APIs return created_at and expires_at as integers. Converting them is the quickest way to see whether a token has already expired.
Setting an expiry time
Use the jump buttons or type a date, then copy the Unix value straight into your config or database.
Coordinating across timezones
The world table shows one instant rendered everywhere at once, which settles arguments about when a deploy window actually falls.
Frequently Asked Questions
How do I convert a Unix timestamp to a date?
Paste the number and every readable format appears immediately, including ISO, UTC, local time and how long ago it was.
What is a Unix timestamp?
The number of seconds since the first of January 1970 UTC. It is how most systems store a moment in time, because a single integer is unambiguous.
Is my timestamp in seconds or milliseconds?
Count the digits. Ten is seconds, thirteen is milliseconds. The tool detects this automatically, and you can override it.
Why did my date come out as 1970?
You almost certainly passed seconds to something expecting milliseconds. It is the most common timestamp bug there is.
Does a Unix timestamp have a timezone?
No. It is an absolute instant, identical everywhere. The timezone only appears when you format it for display.
What is ISO 8601?
The international standard date format, like 2026-07-21T14:30:00Z. It sorts correctly as text and is unambiguous, which is why APIs prefer it.
Can I convert a date back to a timestamp?
Yes. Type a date in almost any recognisable format and the Unix value appears alongside everything else.
What is the year 2038 problem?
Systems storing Unix time in a signed 32-bit integer overflow in January 2038. Modern systems use 64-bit values and are unaffected for billions of years.
Why does the clock keep ticking?
So you can grab the current timestamp at the moment you need it. Untick Keep ticking to freeze it.
Is my data uploaded to a server?
No. Everything is calculated in your browser using its own clock and timezone settings.
What are microsecond timestamps?
Sixteen-digit values used by some databases and tracing systems for finer resolution. They are supported here too.
Is this timestamp converter really free?
Completely free, with no limits, no signup and no premium wall.
Last updated: July 21, 2026 · FlipMyFormat Timestamp Converter
Written and maintained by the FlipMyFormat team