BRev Unix timestamp / epoch converter — free
Paste anything — an epoch in seconds, milliseconds, microseconds or nanoseconds, an ISO 8601 or RFC date, or plain English like “next friday 3pm” — and get every format at once: ISO, RFC 2822, HTTP dates, relative time, Discord timestamps and a timezone comparison. Batch-convert whole CSV columns too, all on your device.
What is Unix time?
Unix time (epoch time) counts the seconds elapsed since 00:00:00 UTC on 1 January 1970 — the Unix epoch — ignoring leap seconds. It is timezone-independent: the same number everywhere on Earth, which is why databases, APIs and logs use it.
Negative values are valid and simply mean “before 1970”: −86400 is 31 December 1969.
The year 2038 problem
Systems that store Unix time in a signed 32-bit integer overflow at 2147483647 — 03:14:07 UTC on 19 January 2038. One second later the value wraps to −2147483648, which reads as 13 December 1901.
Modern 64-bit time values postpone the problem by ~292 billion years; the risk lives in old embedded systems, file formats and databases.
Seconds, millis, micros or nanos?
Sources differ, and the digit count usually gives it away for present-day timestamps:
| Digits | Unit | Typical source |
|---|---|---|
| 10 | seconds | Unix, APIs, JWT claims |
| 13 | milliseconds | JavaScript, Java |
| 16 | microseconds | Python, PostgreSQL |
| 19 | nanoseconds | Go, Rust, ClickHouse |