Unix Timestamp Converter

Convert Unix epoch timestamps to human-readable dates and back. Seconds or milliseconds — auto-detected, all in your browser.

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Current Unix Time (seconds)
Timestamp → Date
Date → Timestamp

How to convert a Unix timestamp

  1. Paste a timestamp (like 1752470400) into the top box. Commas and spaces are ignored, and a leading minus sign is allowed for dates before 1970.
  2. Read the result instantly: your local time, UTC, ISO 8601 and a relative description such as “3 days ago”. The green message tells you whether the number was read as seconds or milliseconds.
  3. To go the other way, pick a date and time in the lower box and copy the Unix seconds or milliseconds. Now → converter loads the current time into the top box.

What is a Unix timestamp?

A Unix timestamp (epoch time) counts the seconds since January 1, 1970 at 00:00:00 UTC. Because it is one number with no timezone attached, databases, APIs, JWT tokens and log files use it to record exactly when something happened. Reference points you can paste into the tool:

  • 0 is 1970-01-01T00:00:00Z, the epoch itself.
  • 1000000000 is 2001-09-09T01:46:40Z, the famous billion-second mark.
  • 1700000000 is 2023-11-14T22:13:20Z.
  • 1752470400 is 2025-07-14T05:20:00Z.
  • 2147483647 is 2038-01-19T03:14:07Z, the last second a signed 32-bit integer can hold.

Seconds, milliseconds and the 1e12 rule

Unix tools, most SQL databases and JWT exp claims use seconds (10 digits today). JavaScript's Date.now(), Java and many analytics APIs use milliseconds (13 digits), a number exactly 1,000 times larger. This tool treats any value whose absolute size is 1e12 or more as milliseconds, and anything smaller as seconds. That works for nearly every real date, with three exceptions to watch for:

  • A millisecond timestamp from before 9 September 2001 has only 12 digits, so it is read as seconds and shows a date roughly 30,000 years in the future.
  • A 16-digit microsecond value (used by some databases) is read as milliseconds and shows a date tens of thousands of years away. Divide by 1,000 first.
  • A 19-digit nanosecond value is outside the range JavaScript dates support (about plus or minus 8.64 × 1015 ms) and returns an out-of-range error. Divide by 1,000,000 first.

Time zones, daylight saving and the lower converter

The “Local time” line uses your browser's time zone and locale, so the same timestamp looks different to a colleague in another country; the UTC and ISO 8601 lines never change. The date picker in the lower box is interpreted in your local zone, then converted to UTC seconds, rounded down to a whole second. If you need a timestamp for a specific zone other than yours, work out the UTC equivalent first. During the repeated hour when clocks go back in autumn, a local time such as 01:30 happens twice, and the browser picks one of them. Prefer UTC when exact accuracy matters.

Practical tips

  • Debugging JWTs: the iat, nbf and exp claims are seconds. Paste exp to see whether a token has already expired; the relative line shows “ago” or “in”.
  • Log analysis: convert the first and last timestamps of an incident to ISO 8601 and paste them into your report so readers in any time zone agree.
  • Scheduling: add 86,400 for one day and 3,600 for one hour. Unix time ignores leap seconds, so every day is exactly 86,400 seconds.
  • The relative line is approximate: it counts a month as 30 days and a year as 365 days.

Is it private and safe?

Yes. Every conversion is done by JavaScript inside your browser, and nothing you type is uploaded or logged. The live clock at the top simply reads your own device's time.

Related guide: Unix timestamps explained. You may also need the JSON Formatter when inspecting API responses that contain timestamps.

Frequently asked questions

What is a Unix timestamp?

It is the number of seconds elapsed since January 1, 1970 at 00:00:00 UTC, not counting leap seconds. Because it has no time zone, it is a compact and unambiguous way for computers to store a moment in time.

How does it detect seconds vs milliseconds?

Values of 1,000,000,000,000 (1e12) or more are treated as milliseconds, and smaller values as seconds. That covers every date from late 2001 onward in milliseconds and from 1970 to the year 33658 in seconds.

Why does my timestamp show a date in 1970?

Almost always a millisecond value is being read as seconds, or the number is really a small counter and not a timestamp. A 10-digit number is in seconds. A 13-digit number is milliseconds. Check how many digits you have.

Can it convert negative timestamps?

Yes. A negative number is a moment before January 1, 1970. For example -86400 is December 31, 1969 at 00:00:00 UTC. Digits only are accepted, so decimals like 1752470400.5 are rejected; drop the fraction first.

What is the Year 2038 problem?

Systems that store Unix time in a signed 32-bit integer overflow after 2147483647, which is 03:14:07 UTC on January 19, 2038. Modern 64-bit systems are unaffected, and this tool handles dates far beyond 2038.

Why is the local time different from the UTC time?

Local time applies your device's time zone offset and daylight saving rules. UTC and the ISO 8601 line are the same everywhere, so use them when sharing a time with people in other zones.

Is my data uploaded?

No. All conversion happens locally in your browser with JavaScript, and nothing you type is sent to a server.

Is it free?

Yes. It is completely free, with no sign-up and no limits.

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