Unix Timestamp Converter

About this tool

This tool converts between Unix timestamps and human-readable dates. Enter an epoch value in seconds or milliseconds, pick a date and time, or select Now, and it shows the same instant five ways: Unix seconds, Unix milliseconds, UTC, your local time, and ISO 8601.

A Unix timestamp is the number of seconds elapsed since 1970-01-01 00:00:00 UTC. It turns up in log lines, JWT exp and iat claims, database columns, cloud billing records and cron audit output, and it is deliberately timezone-free, which is why it needs translating before anyone can reason about it. Conversion runs in your browser using the built-in date functions and nothing is sent to a server. For scheduling rather than converting, see the cron expression generator.

How to use it

Each row of the output is the same moment expressed differently.

• Unix (seconds) — the standard epoch value most APIs and log formats use.
• Unix (milliseconds) — what JavaScript, Java and many JSON APIs emit; the same number with three more digits.
• UTC — the absolute reference. Use it when comparing events across regions.
• Local — the same instant in your browser's timezone, daylight saving included.
• ISO 8601 — what to write into config, tickets and documentation: unambiguous, and it sorts lexicographically.

Common questions

Is my timestamp in seconds or milliseconds?

Count the digits. A current epoch in seconds is 10 digits; in milliseconds it is 13. The tool applies that rule automatically and treats input longer than 10 characters as milliseconds.

What is the year 2038 problem?

Systems storing the timestamp in a signed 32-bit integer overflow on 19 January 2038, when the value passes 2147483647 and wraps to a negative number read as 1901. Modern 64-bit time types are unaffected; legacy applications and embedded devices may not be.

Why does local time differ from what my server logged?

Local time is rendered in your browser's timezone, while most servers log in UTC. The underlying Unix value is identical; only the presentation changes. Compare the UTC row when correlating incidents across hosts.