Unix Timestamp Converter
Convert a Unix timestamp (epoch) to a human date and back. Seconds or milliseconds, with UTC, ISO 8601, local and relative output. Runs entirely in your browser. Last reviewed 2026-06-19.
Current Unix time: …
Timestamp → date
- UTC
- —
- ISO 8601
- —
- Local
- —
- Relative
- —
Date → timestamp
What a Unix timestamp is
A Unix timestamp (epoch / POSIX time) counts the seconds since
1 January 1970 00:00:00 UTC, ignoring leap seconds. Because it is a single number in
UTC, it stores an exact instant independent of timezone — which is why databases, logs and APIs
use it. For example, 1700000000 is Tue, 14 Nov 2023 22:13:20 GMT (ISO 8601:
2023-11-14T22:13:20.000Z).
Seconds vs. milliseconds
Classic Unix time is in seconds (a current value is 10 digits). JavaScript and many platforms use milliseconds (13 digits). If you paste a 13-digit value with the unit set to “Auto-detect”, this tool treats it as milliseconds. Common intervals in seconds:
| Interval | Seconds |
|---|---|
| Minute | 60 |
| Hour | 3,600 |
| Day | 86,400 |
| Week | 604,800 |
| Year (365 days) | 31,536,000 |
The Year 2038 problem
Software that stores the timestamp in a signed 32-bit integer can only count up to 2,147,483,647 seconds — reached at 03:14:07 UTC on 19 January 2038. Past that the value overflows to a negative number. The fix is to store time in 64-bit integers, which all modern systems do.
Frequently asked questions
- What is a Unix timestamp?
- A Unix timestamp (also called epoch or POSIX time) is the number of seconds that have elapsed since 00:00:00 UTC on 1 January 1970 (the "Unix epoch"), not counting leap seconds. It is a timezone-independent way to store an instant in time.
- Is the timestamp in seconds or milliseconds?
- Unix timestamps are classically in seconds (10 digits for current dates). JavaScript, Java and many APIs use milliseconds (13 digits). This tool lets you pick the unit, and auto-detects 13-digit input as milliseconds.
- What is the Year 2038 problem?
- Systems that store the timestamp in a signed 32-bit integer overflow on 19 January 2038 at 03:14:07 UTC, when the value exceeds 2,147,483,647. Modern 64-bit systems are unaffected; the fix is to store time in 64-bit integers.
- Does the conversion happen on your servers?
- No. It runs entirely in your browser with the native Date API, so your values are never uploaded. It also works offline once loaded.