Tool 008 / dev / free / runs locally
Unix Timestamp Converter
Convert a Unix epoch timestamp into a readable UTC and local date, or pick a date and time to get the matching epoch value. It handles both seconds and milliseconds and updates live as you type. Everything runs in your browser, so nothing is sent to a server.
Timestamp to date
Date to timestamp
How it works
A Unix timestamp counts the seconds (or milliseconds) since the Unix epoch, midnight UTC on 1 January 1970. This tool converts in both directions: paste an epoch value to see the date in UTC and in your browser's local time zone, or pick a date and time to get the epoch back in both seconds and milliseconds.
The seconds-versus-milliseconds toggle matters because the two differ by a factor of 1000. A 10-digit number is almost always seconds; a 13-digit number is almost always milliseconds. JavaScript's Date works in milliseconds internally, so the tool multiplies by 1000 when you select Seconds. The Now button fills in the current moment in whichever unit is selected.
Conversion is local to your browser. The local-time output uses your operating system's time zone and respects daylight saving, while the UTC output is fixed, which is the safe value to store in a database or log.
How to use it
- To go from a timestamp: type the epoch number and pick Seconds or Milliseconds.
- Read the date back in both UTC and your local time zone, or click Now for the current moment.
- To go the other way: pick a date and time in the Date to timestamp picker.
- Copy the epoch in seconds or milliseconds from the result cards.
Worked examples
Input: 1700000000 (Seconds)
Output: 2023-11-14 22:13:20 UTC, shown alongside the same instant in your local time.
A 10-digit value read as seconds.
Input: Date picker set to 2000-01-01 00:00:00 local
Output: Epoch 946684800 in seconds (946684800000 in milliseconds) if your local zone is UTC.
Your actual epoch shifts by your UTC offset.
Edge cases and limits
- The timestamp-to-date side only accepts a whole number; decimals or stray characters show Enter a whole number timestamp.
- Negative timestamps are accepted and map to dates before 1970, which is useful but easy to enter by accident.
- The local-time output depends on your device's time-zone setting, so the same timestamp shows different local clock times on different machines. The UTC value never changes.
- JavaScript dates are reliable from about the year 271821 BC to 275760 AD; values outside that range show as invalid.
Common mistakes
- Feeding a millisecond value while the toggle says Seconds, which lands you roughly 50000 years in the future. Match the unit to the digit count.
- Storing local time instead of UTC. Always persist the UTC value and convert for display.
- Forgetting that the date picker interprets your input as local time, so the resulting epoch already includes your offset.
Frequently asked questions
What is a Unix timestamp in seconds versus milliseconds?+
A Unix timestamp counts the time elapsed since January 1, 1970 UTC. Most systems store it in seconds, while JavaScript and many APIs use milliseconds, which are 1000 times larger. This converter detects and supports both.
How do I convert a Unix timestamp to my local time zone?+
Enter the epoch value and the tool shows both the UTC datetime and the local datetime based on your device clock and time zone settings, so you can read whichever you need.
How do I convert a date back into a Unix timestamp?+
Use the date and time picker. As you change the value the tool instantly shows the matching epoch in seconds and in milliseconds, ready to copy.
Related tools
More Developer tools that run entirely in your browser.