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Epoch Milliseconds Converter (JavaScript Date.now)
Convert 13-digit millisecond timestamps from JavaScript and Java to dates and back.
📚 Official sources: MDN Date
We build every tool from the official rules and re-check them when they change. Always confirm with the official source before you rely on a result.
🛠️ Spotted a mistake or an out-of-date rule? Tell us
Questions people ask
What is a Unix timestamp?+
The number of seconds since 1 January 1970 at 00:00:00 UTC (the Unix epoch). It's the same everywhere in the world, so it's the standard way to store time in databases and APIs.
Seconds or milliseconds?+
Unix tools, PHP and most APIs use seconds (10 digits today). JavaScript's Date.now() and Java use milliseconds (13 digits). This converter detects which one you pasted by the number of digits.
What happens in 2038?+
Systems that store Unix time in a signed 32-bit number overflow on 19 January 2038 at 03:14:07 UTC (timestamp 2147483647). Modern 64-bit systems are not affected.