Unix Timestamp Converter: Convert Dates and Times
Convert a Unix timestamp to a date or a local date and time to seconds and milliseconds. Compare local time with UTC.
This tool processes its main input in your browser and does not send it to an external API. Fonts and interface assets may load from external providers.
Unix Timestamp Converter: Convert Dates and Times
A Unix timestamp represents time as a numeric offset from an epoch. APIs, databases and logs often use timestamps instead of formatted dates.
Seconds and milliseconds are easy to confuse: the same digits can represent times a thousandfold apart. This tool lets you choose the input unit and displays both a local date and a UTC value.
When is it useful?
- Reading a createdAt timestamp in an API response.
- Creating seconds and milliseconds values for a test date and time.
How to use it
- Choose Timestamp to Date or Date to Timestamp.
- For a timestamp input, select seconds or milliseconds explicitly; for the reverse direction, choose a date and time in your device's local zone.
- Compare the displayed local value and UTC ISO value before copying a result into another system.
Example
Input: 0 seconds
Output: 1970-01-01 00:00:00 UTC; 0 Unix seconds and 0 Unix milliseconds
Who is it for?
- Backend and web developers
- People investigating timestamps in logs
- Learners comparing local time with UTC
Privacy and limitations
Conversion runs in the browser and does not send the time value to an external API.
Frequently asked questions
Is a timestamp in seconds or milliseconds?
Check the source system. JavaScript date APIs often use milliseconds, while many Unix tools return seconds; the number of digits is a clue, not proof.
Why do UTC and local time differ?
UTC is a shared time standard. The local display applies the device's time-zone and historical daylight-saving rules.
What is the Unix epoch?
The common Unix epoch starts at 1970-01-01 00:00:00 UTC. A timestamp of zero represents that instant.
What does a negative timestamp mean?
Yes. It can represent a time before the Unix epoch, subject to the supported date range of the browser and consuming system.