Unix Timestamp Converter — Epoch Time to Date and Back
A Unix timestamp (also called epoch time or POSIX time) is the number of seconds elapsed since January 1, 1970 at 00:00:00 UTC. It is how most operating systems, databases, and APIs store points in time, because a single integer is compact, unambiguous, and easy to compare. This converter turns a timestamp into a human-readable date — shown in both your local time zone and UTC — and converts any date and time back into its timestamp.
The tool handles both seconds and milliseconds, the two resolutions you will meet in practice: Unix tools and most APIs use seconds (10 digits today), while JavaScript's Date.now() and many logging systems use milliseconds (13 digits). A live clock shows the current timestamp updating in real time, which is handy for quick sanity checks while debugging.
How it works
A Unix timestamp counts the seconds elapsed since the epoch, 1970-01-01T00:00:00Z, ignoring leap seconds. The converter multiplies a seconds value by 1,000 to construct a JavaScript Date, which is then rendered in your local time zone and in UTC using the browser's internationalization API. The reverse direction parses your date and time, interprets it in the selected zone, and returns getTime() ÷ 1000 (seconds) or getTime() (milliseconds).
Use cases
- Decoding timestamp fields in API responses, log files, and database dumps
- Generating a timestamp for a specific date to use in a query or script
- Checking the current Unix time while debugging token expirations (JWT exp/iat claims)
- Telling seconds from milliseconds when a date renders decades off
- Comparing event times across servers logging in different time zones
- Converting scheduled job times between UTC and local time
Frequently asked questions
What is a Unix timestamp?
A Unix timestamp is the number of seconds that have elapsed since January 1, 1970 at 00:00:00 UTC, a reference point called the Unix epoch. It is the standard way computers store and exchange points in time: a single integer that is time-zone independent and trivially comparable. For example, 1750000000 corresponds to June 2025.
How do I tell if a timestamp is in seconds or milliseconds?
Count the digits: current timestamps in seconds have 10 digits, while milliseconds have 13. If you convert a milliseconds value as if it were seconds, the resulting date lands tens of thousands of years in the future; do the reverse and you land shortly after 1970. This converter lets you toggle between the two resolutions to check quickly.
Do Unix timestamps have a time zone?
No. A timestamp identifies a single instant that is the same everywhere on Earth — it is always anchored to UTC. Time zones only enter the picture when you format that instant as a human-readable date, which is why the same timestamp shows different wall-clock times in São Paulo, Madrid, and New York.
What is the year 2038 problem?
Systems that store timestamps as signed 32-bit integers overflow on January 19, 2038 at 03:14:07 UTC, when the count exceeds 2,147,483,647. Affected systems would wrap around to a date in 1901. Modern operating systems, databases, and languages have largely moved to 64-bit time values, which push the limit billions of years out, but old embedded devices and legacy formats can still be affected.
How do I get the current Unix timestamp in code?
In JavaScript, Math.floor(Date.now() / 1000) returns seconds (Date.now() itself returns milliseconds). In Python, use int(time.time()). In a Unix shell, run date +%s, and in SQL databases you can use functions like UNIX_TIMESTAMP() in MySQL or EXTRACT(EPOCH FROM NOW()) in PostgreSQL. All of these return the same instant regardless of the machine's time zone.