What is a Unix timestamp?

A Unix timestamp is the number of seconds (or milliseconds) that have elapsed since 00:00:00 UTC on 1 January 1970, the Unix epoch. It is a timezone-independent way to represent a specific moment in time.

How do I tell the difference between seconds and milliseconds?

A 10-digit value (like 1735689600) is almost always seconds; a 13-digit value (like 1735689600000) is almost always milliseconds. The Auto-detect unit button uses this rule of thumb.

Do timestamps carry timezone information?

No. A Unix timestamp represents the same absolute moment everywhere on Earth. The timezone only matters when you format the timestamp back into a human-readable date.

Does this tool work offline?

Yes. After the page loads, every conversion runs locally in your browser using the built-in Date and Intl.DateTimeFormat APIs. No server round trip is ever made.

Unix Timestamp Converter

Convert between Unix timestamps and human dates. Supports seconds and milliseconds, UTC and your local timezone.

Current Unix timestamp

Seconds

...

Milliseconds

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Timestamp → Date

Enter a Unix timestamp to see the equivalent date and time.

Timestamp

Unit

Enter a positive or negative integer to see the corresponding date.

Date → Timestamp

Pick a date and time to see the equivalent Unix timestamp.

Date & time (UTC)

Output unit

Pick a valid date to get the timestamp.

How to use the Unix Timestamp Converter

Convert a Unix timestamp to a human date or a date to a Unix timestamp, in seconds or milliseconds.

Read the current Unix timestamp at the top of the page — it updates every second in both seconds and milliseconds form.
To convert a timestamp to a date, paste the value into the Timestamp field and pick Seconds or Milliseconds. Use Auto-detect unit if you are not sure — 10-digit values are seconds, 13-digit values are milliseconds.
Read the equivalent date in your local timezone and in UTC, along with the ISO 8601 string and a relative time like "3 hours ago".
To convert a date to a timestamp, use the Date → Timestamp box: pick a date and time in your local zone and choose Seconds or Milliseconds for the output.
Copy the resulting timestamp (click the value to select it) and paste it into your log file, database, or API call.

Frequently asked questions

What is a Unix timestamp?: A Unix timestamp is the number of seconds (or milliseconds) that have elapsed since 00:00:00 UTC on 1 January 1970, the Unix epoch. It is a timezone-independent way to represent a specific moment in time.
How do I tell the difference between seconds and milliseconds?: A 10-digit value (like 1735689600) is almost always seconds; a 13-digit value (like 1735689600000) is almost always milliseconds. The Auto-detect unit button uses this rule of thumb.
Do timestamps carry timezone information?: No. A Unix timestamp represents the same absolute moment everywhere on Earth. The timezone only matters when you format the timestamp back into a human-readable date.
Does this tool work offline?: Yes. After the page loads, every conversion runs locally in your browser using the built-in Date and Intl.DateTimeFormat APIs. No server round trip is ever made.