How to use the Unix Timestamp Converter
- The top panel shows the current Unix time, updating every second — click Copy seconds or Copy ms.
- Paste a timestamp into Timestamp → date. Seconds, milliseconds, microseconds and nanoseconds are detected from the number of digits, or pick the unit yourself.
- Read the result in your chosen time zone, in UTC, as ISO 8601 and as relative time (“3 days ago”).
- To go the other way, pick a date and time in Date → timestamp; it is interpreted in the selected time zone.
What is a Unix timestamp?
A Unix timestamp (also called epoch time or POSIX time) is the number of seconds that have elapsed since 00:00:00 UTC on 1 January 1970, the “Unix epoch”. It is a single integer with no time zone attached, which makes it ideal for storing and comparing moments in time: 1761350400 means exactly the same instant everywhere in the world. Converting it to a calendar date only becomes time-zone dependent when you display it.
Seconds, milliseconds, microseconds, nanoseconds
Different platforms count in different units, and mixing them up is the most common timestamp bug (it produces dates in 1970 or in the year 57,000). The converter detects the unit from the number of digits for present-day dates:
| Unit | Digits (today) | Used by |
|---|---|---|
| Seconds | 10 | Unix/Linux, PHP time(), Python time.time(), JWT claims |
| Milliseconds | 13 | JavaScript Date.now(), Java currentTimeMillis() |
| Microseconds | 16 | PostgreSQL internals, Python datetime precision |
| Nanoseconds | 19 | Go UnixNano(), InfluxDB |
For example, 25 October 2025 00:00 UTC is 1761350400 in seconds and 1761350400000 in milliseconds.
Getting the current timestamp in code
- JavaScript:
Math.floor(Date.now() / 1000) - Python:
int(time.time()) - PHP:
time() - Bash:
date +%s— anddate -d @1761350400to convert back (GNU) - SQL (PostgreSQL):
extract(epoch from now()); MySQL:UNIX_TIMESTAMP()
Time zones and ISO 8601
When you convert a date to a timestamp, the same wall-clock time means different instants in different places: 09:00 in Berlin is 07:00 UTC in summer but 08:00 UTC in winter. That's why the date input is interpreted in the time zone you select, with daylight-saving rules from your browser's time-zone database. For exchanging dates as text, use ISO 8601 with an explicit offset, such as 2026-10-25T09:00:00+01:00 or 2026-10-25T08:00:00Z (the Z means UTC). Leap seconds are not counted in Unix time, so every day is exactly 86,400 seconds.
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 — and wrap around to 1901. Modern operating systems and languages use 64-bit timestamps, but embedded devices, old file formats and some database columns (e.g. MySQL TIMESTAMP) are still affected. Need to measure the gap between two dates? Use the Date Difference Calculator, or convert between zones with the Time Zone Converter.
Tools that pair well with the Unix Timestamp Converter
- UUID Generator — Create cryptographically random UUIDs (v4) or sortable, timestamp-based UUIDs (v7) in bulk, then copy or download them.
- Cron Expression Generator — Build a crontab schedule without memorising the syntax — or paste an existing expression to see what it means in plain English and exactly when it will run next.
- Base64 Encode / Decode — Convert text to Base64 and back with full UTF-8 support (accents, emoji), switch to URL-safe Base64, or drop a file to get its Base64 string or data URI.
- URL Encode / Decode — Percent-encode text for safe use in URLs, decode encoded strings back to readable text, and break any URL down into its parts and query parameters.
Frequently asked questions
How do I know if a timestamp is in seconds or milliseconds?
Is a Unix timestamp UTC?
Can Unix timestamps be negative?
-86400 is 31 December 1969 00:00:00 UTC. The converter handles them.