Unix Timestamp Converter
Convert Unix epoch timestamps to human-readable dates, ISO strings, and relative times. Convert backwards from dates to Unix seconds instantly.
Unix to Date
Date to Unix
Note: Your browser evaluates datetime input against your system's local timezone settings.
What is a Unix Timestamp Converter?
A unix timestamp converter is an essential developer tool used to translate Unix Epoch Time into a standard, human-readable date format, and vice versa. The Unix epoch (or Unix time) is the number of seconds that have elapsed since midnight on January 1, 1970 (UTC), ignoring leap seconds. This numerical system is widely used across operating systems, file formats, and backend databases because it provides a single, timezone-independent integer to represent a specific moment in time.
Because humans cannot easily read "1704067200" and know what day it represents, our converter allows you to instantly parse that integer into standard formats like ISO 8601 or RFC 2822, or convert a specific date and time back into a machine-readable integer payload for API requests.
How to use the Timestamp Converter
- Unix to Date: Enter the timestamp integer into the left panel. The tool automatically detects if you've entered seconds (standard) or milliseconds (common in JavaScript). Choose your desired timezone from the dropdown and click Convert.
- Date to Unix: Use the native date picker on the right panel to select a specific date and time. Click convert to see the exact Unix integer in both seconds and milliseconds.
- Live Clock: The top panel provides a real-time, ticking display of the current epoch time.
- Copy Data: Click any generated output value (like the ISO string or the generated seconds) to instantly copy it to your clipboard.
Features of this Tool
- ✓ 100% client-side — your time queries never leave the browser.
- ✓ No sign-up or account required.
- ✓ Auto-Detection: Intelligently guesses whether your input is in seconds or milliseconds.
- ✓ Timezone Support: Format outputs using standard `Intl.DateTimeFormat` across major global timezones like EST, GMT, and JST.
- ✓ Relative Time: Instantly see if a timestamp is "in 3 hours" or "5 days ago".
- ✓ Bidirectional: Effortlessly convert from numbers to dates, and from dates back to numbers.
Frequently Asked Questions
Why does JavaScript use milliseconds instead of seconds?
While the original POSIX/Unix specification defines the epoch in seconds, JavaScript's `Date.now()` and internal date objects operate in milliseconds for higher precision. If you are feeding a JS timestamp into a system expecting standard Unix time (like a MySQL database or a PHP backend), you must divide it by 1000.
What is the Year 2038 Problem (Y2K38)?
The Year 2038 problem is a time formatting bug. Systems that store the Unix timestamp as a signed 32-bit integer will run out of space to represent time on January 19, 2038. At that moment, the integer will "wrap around" and represent a negative number, meaning systems will interpret the date as December 13, 1901. Modern 64-bit systems have already resolved this.
Are leap seconds included in Unix time?
No. By definition, Unix time does not count leap seconds. Every day in Unix time is strictly 86,400 seconds long. When a leap second is added globally, Unix systems generally handle it by repeating the same second twice.
Is this converter accurate for my local timezone?
Yes. The right panel ("Date to Unix") relies on your browser's native `datetime-local` input, which evaluates the date you select against the local timezone settings configured on your operating system.