D

Unix Timestamp Converter

Convert Unix timestamps to human-readable dates and back — supports seconds and milliseconds.

Runs 100% in your browser — nothing is uploaded

About this tool

Unix timestamps represent a point in time as the number of seconds (or milliseconds) elapsed since 00:00:00 UTC on January 1, 1970 (the Unix epoch). This converter translates between Unix timestamps and ISO 8601 dates in both directions, and also shows the current timestamp live.

Timestamps are the backbone of logging, APIs, databases, and system programming. Converting them to human-readable form is a daily task for developers debugging events, interpreting log files, or understanding JWT expiry times (which use exp as a Unix timestamp in seconds). This tool auto-detects whether your input is in seconds (10 digits) or milliseconds (13 digits).

Output includes: ISO 8601 UTC string, local datetime string using your browser's timezone, relative time ("3 hours ago"), day of week, and the Julian Day Number. All computation uses the browser's Date API — no network call, no timezone database server, no external dependencies. The current timestamp updates every second so you can copy a live value at any moment.

Frequently asked questions

Is the timestamp in seconds or milliseconds?
Unix timestamps from most POSIX systems and databases are in seconds (10 digits). JavaScript's Date.now() returns milliseconds (13 digits). This tool auto-detects based on the number of digits — 10-digit inputs are treated as seconds, 13-digit inputs as milliseconds.
What timezone does the converter use?
UTC is always shown. Local time is displayed using your browser's system timezone — the same timezone your operating system is set to. No timezone selection is needed for basic conversion.
When does the Unix epoch end (Year 2038 problem)?
Systems that store Unix time as a 32-bit signed integer will overflow on January 19, 2038. Modern systems and databases use 64-bit integers, which extend the range to the year 292 billion — effectively forever.

Related tools

Date Difference Calculator

Calculate the exact difference between two dates in days, weeks, months, years, hours, and minutes.