How it works
A Unix timestamp counts the time elapsed since January 1, 1970 at midnight UTC. It is how most systems store dates, but it is not readable at a glance. Paste a timestamp and this tool shows the date in ISO 8601 UTC, in the RFC 7231 HTTP format, in your local time, as relative time (“3 hours ago”), with its ISO week and day of the year.
The input detects the unit from the number of digits: seconds (as in date +%s or JWTs), milliseconds (like Date.now() in JavaScript or Java), microseconds (Python, PostgreSQL) and nanoseconds (Go, Prometheus). It also works the other way around: paste an ISO 8601 date or text like 2026-10-29 12:00 and you get the timestamp in seconds and milliseconds. Type now for the current time.
The time zones table shows the same instant in cities across the Americas, Europe and Asia with their offset from UTC, including the daylight saving time in effect on that date. It is what you need to read a production log, coordinate a deploy across teams or check when a token expires.
Everything is computed in your browser with Date and Intl. If you paste a timestamp on the home page, ByteKnife recognizes it and opens it here.
Examples
Unix seconds to a date
1793318400
Unix (s) 1793318400 Unix (ms) 1793318400000 ISO 8601 UTC 2026-10-30T00:00:00.000Z RFC 7231 Fri, 30 Oct 2026 00:00:00 GMT ISO week 2026-W44 New York Oct 29, 2026, 8:00 PM (GMT-4) Madrid Oct 30, 2026, 1:00 AM (GMT+1)
ISO 8601 date to Unix
2026-10-29T12:00:00Z
Unix (s) 1793275200 Unix (ms) 1793275200000 RFC 7231 Thu, 29 Oct 2026 12:00:00 GMT
Frequently asked questions
How does it know whether the number is in seconds or milliseconds?
By the number of digits: up to 11 is read as seconds, up to 14 as milliseconds, up to 17 as microseconds and more as nanoseconds. The chosen unit is shown next to the input.
What if the date has no time zone?
A date such as 2026-10-29 12:00 without Z or an offset is read as your local time, and the tool tells you so. Add Z for UTC or an offset such as -03:00 to avoid ambiguity.
Do the time zones account for daylight saving time?
Yes. Zones are computed with the IANA database that ships with your browser through Intl, so each city's offset is the one that applies on that exact date.