Unix timestamp converter
Convert between Unix timestamps and human-readable dates.
Seconds or milliseconds
A Unix timestamp counts from 1 January 1970 UTC. The recurring confusion is the unit: most backends and databases count seconds, while JavaScript's Date.now() counts milliseconds. Feed one to something expecting the other and you land in 1970 or somewhere around the year 56000.
Both are accepted here, distinguished by length — ten digits is seconds, thirteen is milliseconds — and both interpretations are shown so you can see immediately which your system meant.
Both directions
Paste a timestamp to get readable dates, or paste a date such as 2026-09-05 or 5 Sep 2026 14:30 to get the timestamp back. Leave the field empty and it shows the current time, which is what most people arrive for.
UTC and your local time
Timestamps are always UTC — that is the point of them. The result is shown in both UTC and your device's local zone, because most timestamp bugs are really timezone bugs: a log line in UTC compared against a screenshot in local time, with the discrepancy blamed on the code.
The relative reading ("in 3 days", "2 hours ago") is the fastest way to sanity-check a value. A token expiry that reads "3 hours ago" explains the failure immediately.
The 2038 problem
Systems storing timestamps as signed 32-bit integers overflow on 19 January 2038. Modern platforms use 64-bit values and are unaffected, but embedded systems and old database columns still carry the limit.
Related
Debugging a token expiry usually starts at the JWT decoder, which decodes these claims for you.
Common questions
Seconds or milliseconds?
Ten digits is seconds, thirteen is milliseconds. Both are accepted and both readings are shown.
What is a Unix timestamp?
The number of seconds since 1 January 1970 UTC — a timezone-free way to represent an instant.
Why does my date look wrong by hours?
Almost always a timezone difference. Both UTC and your local time are shown so you can see which is which.
What is the 2038 problem?
Signed 32-bit timestamps overflow on 19 January 2038. Modern 64-bit systems are unaffected.
Is anything sent to a server?
No, conversion happens in your browser.