Unix Timestamp Converter
Epoch time to a readable date, and back again.
Seconds since 1 January 1970 UTC. Milliseconds (13 digits), microseconds and nanoseconds are recognised by their length.
Unix tools use seconds; JavaScript's Date.now() and Java use milliseconds.
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How this was worked out
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Guide: One number, one instant2 min read
One number, one instant
A Unix timestamp counts the seconds since midnight UTC on 1 January 1970. It is the format of logs, databases, APIs, cookies and JWTs, because it is a single number with no time zone in it: 1767225600 is the start of 2026 in London, in Tokyo and in New York — where it is still 7 pm on the 31st.
Paste the number and the page shows the date in ISO 8601, written out in UTC, in your browser's time zone, and how long ago or how far ahead it is. In the other mode, pick a date, a time and whether that time is UTC or yours, and the timestamp comes out in seconds and in milliseconds.
Seconds, milliseconds, or smaller
The usual mistake is the unit. Unix tools, PHP and Python use seconds; JavaScript and Java use milliseconds; some databases and tracing systems store microseconds or nanoseconds. Milliseconds read as seconds land in the year 55,000. So the unit is detected from the length — 10 digits for seconds, 13 for milliseconds — and the page says which it assumed, with a setting to choose by hand.
Time zones, and 2038
Store and send times in UTC and convert to a zone only when showing them to a person; mixing the two causes half of all date bugs. Systems that keep seconds in a signed 32-bit integer stop on 19 January 2038, when the number overflows. To add days to a date, use the date calculator; to read a token's expiry, the JWT decoder.
Frequently asked questions
What is a Unix timestamp?
The number of seconds since 00:00:00 UTC on 1 January 1970, not counting leap seconds. It is how most systems store a moment in time, because it is one number with no time zone attached: 1767225600 is the same instant everywhere.
Is my timestamp in seconds or milliseconds?
Count the digits. A current date in seconds has 10 digits (1767225600); in milliseconds, 13 (1767225600000), which is what JavaScript's Date.now() returns. Sixteen digits is microseconds and nineteen nanoseconds. The page detects the unit from the length and says which one it assumed.
Why does the date show a different hour than I expected?
Because the timestamp is UTC and your clock is not. The page shows both: the UTC time, and the same instant in the time zone your browser is set to. São Paulo is three hours behind UTC; New York four or five, depending on daylight saving.
What is the year 2038 problem?
Systems that store seconds in a signed 32-bit integer run out at 2147483647, which is 03:14:07 UTC on 19 January 2038. After that the number wraps to a negative value, a date in 1901. Modern systems use 64 bits; old embedded devices and databases may not.
Is anything sent anywhere?
No. The conversion runs in this tab and works offline.