Unix Timestamp to Date Converter
Convert Unix timestamps to human-readable dates, detect seconds versus milliseconds, and generate Unix time from UTC or local date inputs.
How to convert a Unix timestamp to a date
A Unix timestamp (also called Epoch time or POSIX time) is the number of seconds that have elapsed since January 1, 1970 00:00:00 UTC, a moment known as the Unix epoch. It is the most widely used time representation in computing: databases, APIs, log files, JWTs, and programming languages all store or transmit time as Unix timestamps.
This converter handles both seconds-based timestamps (10 digits, e.g. 1711468800) and millisecond-based timestamps (13 digits, e.g. 1711468800000) automatically. It outputs the result in UTC, your local timezone, ISO 8601 format, and as a human-friendly relative description like "3 hours ago".
Unix timestamp examples
- Convert 1711468800 to a human-readable date
- Check whether an API timestamp is in seconds or milliseconds
- Convert a date like "March 26, 2025 12:00 PM" to a Unix timestamp
- Decode a JWT exp claim to see when a token expires
- Find the Unix timestamp for midnight UTC on a specific date
How to use this Unix timestamp to date converter
- To decode a timestamp: paste the numeric value into the "Timestamp to Date" field and click "Convert".
- To encode a date: use the "Date to Timestamp" section. Pick a date and time using either the local-time or UTC input, and the corresponding Unix timestamp appears below.
Unix timestamp FAQ
What is the difference between seconds and milliseconds
timestamps?
A seconds-based timestamp is typically 10 digits (e.g. 1711468800)
and counts whole seconds since the epoch. A milliseconds-based
timestamp is 13 digits (e.g. 1711468800000) and includes sub-second
precision. JavaScript's Date.now() returns milliseconds;
most server-side languages default to seconds.
Why does my timestamp show a different time than I expected?
Unix timestamps are always in UTC. If the displayed local time looks off, check that your system timezone is set correctly. The converter shows both UTC and your local timezone so you can compare.
What is the Year 2038 problem?
Systems that store Unix time as a signed 32-bit integer will overflow on January 19, 2038. Modern systems use 64-bit integers, which push the limit billions of years into the future. This tool uses JavaScript's native number type and handles dates well beyond 2038.
Can I convert negative timestamps?
Yes. A negative Unix timestamp represents a date before January 1,
1970. For example, -86400 corresponds to December 31, 1969.
Privacy
All conversions happen entirely in your browser using JavaScript's
built-in Date API. No timestamps or dates are sent to any server.