Epoch seconds — now
—
Epoch milliseconds
—
ISO 8601 UTC
—
Difference between two timestamps
and
Batch — one timestamp per line (up to 500)
About Timestamp Converter
Convert Unix epoch timestamps to ISO 8601 dates and back, in any time zone, with batch conversion and duration maths.
What it does
Paste an epoch value and get a readable date in the zone you choose, or go the other way. Seconds and milliseconds are both handled, and a batch mode converts a whole column of timestamps at once — the usual case when you are reading a log file or a database export.
Seconds or milliseconds
The most common mistake with epoch values is a factor of a thousand: Unix tools and Postgres emit seconds, while JavaScript's Date.now() and most JSON APIs emit milliseconds. A ten-digit number is seconds; thirteen digits is milliseconds. Getting it wrong puts you in 1970 or in the year 55000.
Common questions
- How do I tell seconds from milliseconds?
- Count the digits. Ten digits is seconds (current dates begin with 17…), thirteen is milliseconds. The tool detects the likely unit and lets you override it.
- What is the year 2038 problem?
- A signed 32-bit epoch counter overflows on 19 January 2038. Anything storing timestamps in a 32-bit integer breaks then; 64-bit storage does not.
- Can I convert a whole list at once?
- Yes — batch mode takes one timestamp per line and converts the lot.
- Does it handle negative timestamps?
- Yes. Negative values are dates before 1 January 1970.