Epoch
Unix timestamp converter
Seconds or milliseconds?
Unix time counts from 1 January 1970 UTC. The ambiguity that bites people is the unit:
most languages and databases use seconds, while JavaScript's
Date.now() and most JSON APIs written in JavaScript use
milliseconds.
Getting it wrong by a factor of 1000 lands you in 1970 or in the year 56,000. This tool detects the unit from the magnitude — anything with 13 or more digits is treated as milliseconds — and tells you which it assumed.
Timestamps have no timezone
A Unix timestamp is an absolute instant. It is neither UTC nor local — those are presentations of the same number. That is exactly why timestamps are the right thing to store: the ambiguity lives in formatting, not in the data.
The "Treat as UTC" toggle controls how the date field is interpreted when converting the other direction, which is where a timezone genuinely has to be chosen.
The 2038 problem
Systems storing Unix time in a signed 32-bit integer overflow on 19 January 2038 and wrap to 1901. It sounds historical, but it is still present in embedded systems, some C code, and older database columns. If you are choosing a column type today, use 64-bit — or a native timestamp type.
This tool runs entirely in your browser. Nothing you type, paste or open is sent to util.quest or anywhere else — there is no upload and no request to make one. You can disconnect from the network and it will keep working.
Convert Unix timestamps to readable dates and back, in your local timezone or UTC. Handles seconds and milliseconds, shows ISO 8601 and RFC formats, and keeps a live clock so you can grab the current timestamp without thinking about it.
It's one of the free tools in the util.quest collection — nothing to install, and no account needed. Found a bug or want a feature? Reach out at [email protected].
