What is a Unix timestamp?
A Unix timestamp (also called Epoch time or POSIX time) is the number of seconds elapsed since January 1, 1970 00:00:00 UTC. It provides a timezone-independent way to represent a moment in time, widely used in programming, databases, and APIs.
How does auto-detection of seconds, milliseconds, microseconds, and nanoseconds work?
The converter checks the magnitude of your input: fewer than 13 digits → seconds; 13–15 digits → milliseconds; 16–18 digits → microseconds; 19+ digits → nanoseconds. For example, 1710500000 is seconds, 1710500000000 is milliseconds. The detected unit is shown in color below the input.
Is my data sent to a server?
No. All conversions use JavaScript's built-in Date object and Intl APIs. Everything runs locally in your browser. No data is transmitted anywhere.
What timezones are supported?
All IANA timezones recognized by your browser are listed in the dropdown, typically 400+ entries including America/New_York, Europe/London, Asia/Tokyo, Pacific/Auckland, and many more. Your selected timezone is remembered between sessions.
Can I convert negative timestamps (before 1970)?
Yes. Negative Unix timestamps represent dates before January 1, 1970. For example, -86400 represents December 31, 1969. The converter handles these correctly, including the Unix Hex display which will show a negative hex value.