Paste an epoch value in seconds or milliseconds to read it as a date, or pick a date to get its timestamp. All output is in UTC.
Runs in your browser — nothing is uploaded
A Unix timestamp counts the seconds elapsed since 00:00:00 UTC on 1 January 1970, ignoring leap seconds. APIs, databases and log files store times this way because it is a single integer that sorts correctly and avoids time zone ambiguity.
Some systems use milliseconds instead, which gives thirteen digits for present-day dates where seconds would have ten. The converter detects which unit you entered from the number of digits, so you do not need to choose one. Negative values represent dates before 1970.
Every result is shown in UTC, both as ISO 8601 and as an RFC 2822 string, so the output is the same on every machine. Convert to your local zone only at the display layer, where your application knows the user’s preference.
The converter decides from the magnitude. Values with 13 or more digits are treated as milliseconds, which is how JavaScript Date.now() and many Java and Kafka timestamps work. Smaller values are read as seconds, as in most Unix tools and databases.
A 1970 result usually means the value is in milliseconds but was read as seconds, or the number is a small counter rather than a time. The 2038 problem affects systems that store time as a signed 32-bit integer, which overflows at 03:14:07 UTC on 19 January 2038.
ISO 8601 looks like 2026-01-01T00:00:00.000Z and is preferred for APIs and sorting. RFC 2822 looks like Thu, 01 Jan 2026 00:00:00 GMT and is used in email and HTTP headers such as Last-Modified. Both describe the same instant.
If you type a date without a time zone, such as 2026-01-01 10:00, browsers read it in the local time zone of the device. Add Z or an offset like +02:00 to make the result identical everywhere, for example 2026-01-01T10:00:00Z.
For most application work, no. Unix time assumes every day has exactly 86,400 seconds, so it skips leap seconds. Only systems that need sub-second accuracy across a leap second, such as some financial or scientific logs, need to account for the difference.
No. The conversion uses JavaScript Date objects in your browser, so the values you type are not transmitted or stored.