What is the Unix epoch?

The Unix epoch is 1970-01-01T00:00:00Z. Unix timestamps count elapsed time since that moment: seconds (10 digits) or milliseconds (13 digits).

Are Unix timestamps in seconds or milliseconds?

Most Unix timestamps are either 10 digits (seconds) or 13 digits (milliseconds). This tool auto-detects the unit by the number size (seconds vs milliseconds).

What do the ISO 8601 and UTC outputs mean?

ISO 8601 and UTC show the same instant in UTC. The Local output shows the instant converted into your browser’s local timezone.

How do I convert a date into a Unix timestamp?

Enter a local date and time in the date/time field. The tool converts it into Unix seconds and Unix milliseconds.

How does this help with JWT exp/iat?

`iat` and `exp` in JWTs are Unix timestamps. Copy the number from the JWT Decoder output and paste it here. The converter will turn it into a readable UTC and local date/time.

What is the 2038 problem?

The “2038 problem” refers to systems that store Unix time in 32-bit signed seconds. Around 2038-01-19, those systems can overflow and produce incorrect dates. Using milliseconds and 64-bit time storage avoids the issue.

Converter Tools

Unix Timestamp Converter

Unix timestamps are the number of seconds (10 digits) or milliseconds (13 digits) since the Unix epoch.

Now

1788952587 seconds (Unix) · 2026-09-09T11:16:27.553Z

2026-09-09 11:16:27

Unix timestamp (seconds or milliseconds)

Enter a 10-digit Unix timestamp (seconds) or a 13-digit Unix timestamp (milliseconds). We auto-detect.

Date & time (local)

Uses your browser’s local timezone.

Unix seconds

1,788,952,560

Unix milliseconds

1,788,952,560,000

About Unix Timestamp Converter

Unix timestamps are the number of seconds (10 digits) or milliseconds (13 digits) since the Unix epoch. This free Unix Timestamp Converter converts timestamps in both directions: timestamp → ISO 8601 / UTC / local date/time, and local date/time → Unix seconds and milliseconds.

How to Use Unix Timestamp Converter

Paste a Unix timestamp number. We auto-detect 10-digit seconds vs 13-digit milliseconds.
Read the ISO 8601 (UTC), UTC, and local date/time outputs.
To go the other way, enter a local date and time and convert it into Unix seconds and milliseconds.

Unix Timestamp Converter Examples

Unix epoch start

Timestamp `0` converts to 1970-01-01 00:00:00 UTC.

10-digit seconds

A 10-digit value (seconds) is interpreted as Unix time and converted into the matching date/time.

13-digit milliseconds

A 13-digit value (milliseconds) is interpreted as Unix time and converted into the matching date/time.

Frequently Asked Questions about Unix Timestamp Converter

What is the Unix epoch?: The Unix epoch is 1970-01-01T00:00:00Z. Unix timestamps count elapsed time since that moment: seconds (10 digits) or milliseconds (13 digits).
Are Unix timestamps in seconds or milliseconds?: Most Unix timestamps are either 10 digits (seconds) or 13 digits (milliseconds). This tool auto-detects the unit by the number size (seconds vs milliseconds).
What do the ISO 8601 and UTC outputs mean?: ISO 8601 and UTC show the same instant in UTC. The Local output shows the instant converted into your browser’s local timezone.
How do I convert a date into a Unix timestamp?: Enter a local date and time in the date/time field. The tool converts it into Unix seconds and Unix milliseconds.
How does this help with JWT exp/iat?: `iat` and `exp` in JWTs are Unix timestamps. Copy the number from the JWT Decoder output and paste it here. The converter will turn it into a readable UTC and local date/time.
What is the 2038 problem?: The “2038 problem” refers to systems that store Unix time in 32-bit signed seconds. Around 2038-01-19, those systems can overflow and produce incorrect dates. Using milliseconds and 64-bit time storage avoids the issue.

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