What is Unix time?
Unix time counts the seconds since 1 January 1970 00:00:00 UTC (the "epoch"), ignoring leap seconds. It is a simple way to store a moment as one number and is used in logs, databases, APIs and file systems.
Seconds or milliseconds?
A 10-digit number like 1700000000 is seconds; a 13-digit number like 1700000000000 is milliseconds (what JavaScript's Date.now() returns). The converter guesses from the size and tells you which it assumed.
Time zones
A timestamp has no time zone - it is the same instant everywhere. The zone only matters when you display it. This tool shows UTC and your device's local time. Date strings without a zone are read in your local time; add Z for UTC.
The year 2038 problem
Systems that store Unix time in a signed 32-bit integer run out on 19 January 2038. Modern 64-bit systems are not affected.
Frequently asked questions
How do I get the current timestamp in code?
JavaScript: Math.floor(Date.now()/1000). Python: int(time.time()). Bash: date +%s.
What is ISO 8601?
A standard date format like 2025-03-01T12:00:00Z, easy for both people and programs.
Why is my local time different?
Your device shows the time in your own time zone; UTC is shown separately.