Free Unix timestamp converter
Translate between Unix time (seconds since 1970-01-01 UTC) and calendar dates in your timezone. All math happens locally — no server and no upload.
How to use this tool
- 1
Open Unix timestamp converter
Use it for this task: Unix epoch seconds / milliseconds, readable dates, timezone-aware conversion - fast and 100% local.
- 2
Enter a timestamp or date
Paste a Unix timestamp or choose a date value, then switch units or time zones if needed.
- 3
Copy the converted time
Use the formatted date, timestamp, or timezone result in your logs, docs, or code.
Quick facts
| Runs offline? | Yes — pure JavaScript on your device. |
|---|---|
| Seconds or milliseconds? | APIs often use seconds; JavaScript Date uses milliseconds. Both are shown and stay in sync. |
| Which timezone? | The local picker follows your device clock; the ISO line is always UTC for the same instant. |
| Privacy? | Nothing leaves this tab — no network calls for conversion. |
Top use cases
- Unix epoch seconds / milliseconds, readable dates, timezone-aware conversion - fast and 100% local.
- Runs offline?: Yes — pure JavaScript on your device.
- Seconds or milliseconds?: APIs often use seconds; JavaScript Date uses milliseconds. Both are shown and stay in sync.
- Which timezone?: The local picker follows your device clock; the ISO line is always UTC for the same instant.
- Privacy?: Nothing leaves this tab — no network calls for conversion.
FAQ
What is Unix time?▾
A count of seconds (or milliseconds) since 1970-01-01 00:00:00 UTC. JavaScript uses the common POSIX-style instant, shown in ISO as Zulu (UTC).
Why does the ISO string end with Z?▾
Z means UTC. It is the same moment as your local line — only the display format differs.
What about the year 2038 problem?▾
Modern browsers use 64-bit time; this page still clamps to safe JavaScript number limits for display and input.
Is any data sent to a server?▾
No. Safe Local Tools is static; conversion runs entirely in your browser.
Can I paste decimals?▾
Use whole seconds or whole milliseconds only — fractional epoch values are not parsed here.
Does daylight saving time apply?▾
Yes. The local picker uses your operating system timezone rules when converting between an instant and civil time.