About
Paste a timestamp to see the date, or a date to get the timestamp. The two mistakes worth knowing about are the unit and the timezone, and both are described below because both produce answers that look plausible while being wrong.
How to use
Enter a timestamp or a date string and choose the direction. Readable dates use your browser's timezone, so the same timestamp shows a different wall clock time to a colleague elsewhere.
The unit trap
Unix time counts from the start of 1970, and different ecosystems count in different units. Most backends use seconds and most JavaScript uses milliseconds, which is why a value crossing that boundary lands in 1970 or in the distant future. The digit count is the fastest check: ten for seconds, thirteen for milliseconds, and anything else deserves a second look before you trust the conversion.
A timestamp has no timezone
The number is an instant, identical everywhere. Timezones enter only when it is rendered as a date, which is why the same value shows two different wall clock readings on two machines and neither is incorrect. When comparing a log entry against a screenshot, confirm which zone each was rendered in before concluding that the times disagree.
Where these show up
The exp and iat fields inside a JWT, log lines from anything that does not format for humans, database columns storing epoch integers, and scheduling formats that expect a timestamp rather than a date. Reading a token's expiry is probably the most common reason to be here, and it is a quick way to tell an expired credential from a rejected one.
Values that give themselves away
Zero is the epoch itself, the first of January 1970, and it usually means a field was never set rather than that something happened then. Dates in 2038 hint at a signed 32 bit limit somewhere upstream. A cluster of records at exactly midnight suggests a date was stored where a timestamp was expected. The number often says more about the code than about the event.
FAQ
Seconds or milliseconds?
Ten digits is seconds, thirteen is milliseconds. Getting it wrong produces either a date in 1970 or one tens of thousands of years out, and both are obvious once you know to look.
Which timezone does it display in?
Your browser's. A timestamp is a single instant with no timezone attached, so the conversion has to choose one to display.
Is anything uploaded?
No. The arithmetic happens in the page.
Why does my date come out one day off?
Nearly always a date with no time attached, which gets interpreted at midnight in one zone and shows as the previous evening in another.
Related tools
- Developer and text tools
- JSON Formatter
Format, minify and check JSON in the browser.
- URL Encoder and Decoder
Percent encode or decode text, locally.
- User Agent Parser
Break a UA string into browser, OS and device.
- Cookie Converter
Convert between HTTP, JSON and Netscape cookies.
- List Text Cleaner
Deduplicate, sort and tidy a pasted list.
- CSV to Table
Split delimited text into a table, copy as CSV or TSV.