Timestamp Converter
A Unix timestamp counts seconds (or milliseconds) since January 1, 1970 UTC — the standard way computers store points in time, but not human-readable. This tool converts between a timestamp and a readable date in any timezone, in both directions, instantly. Includes a live ticking clock, offsets cheat sheet, ISO 8601 formatting, relative time calculation, and calendar information.
How to use
- Paste a Unix timestamp (seconds or milliseconds) to see the readable date, click "Current" to load current timestamp, or click "Clear" to reset.
- Search or select any timezone using the dynamic timezone search datalist.
- View formatted outputs in ISO 8601, RFC 2822, UTC, Local, and relative time alongside calendar stats.
- Pick a date/time under 'Date/Time ➔ Unix Timestamp' to instantly generate Unix seconds and milliseconds.
- Pause/resume the live ticking clock in the sidebar, or copy its values with one click.
- Everything runs in your browser — no data is sent anywhere.
FAQ
Seconds or milliseconds — how do I know which one I have?
A 10-digit number (e.g. 1735689600) is seconds; a 13-digit number (e.g. 1735689600000) is milliseconds. This tool detects which one automatically.
Why does a timestamp represent different local times in different timezones?
A Unix timestamp is a single, unambiguous point in time (always UTC internally) — "timezone" only affects how that instant is *displayed*, e.g. as a local wall-clock time.
Is a Unix timestamp affected by daylight saving time?
No — the timestamp itself never changes. Only the human-readable representation in a DST-observing timezone shifts by an hour depending on the time of year.
What is ISO 8601 format and why is it useful?
ISO 8601 is an international standard for formatting dates and times (e.g. YYYY-MM-DDTHH:mm:ss.sssZ). It is highly readable, easy for databases and API systems to parse, sorting-friendly, and prevents ambiguity across regions.
How does the relative time feature work?
The tool calculates the duration between your parsed date and the current instant, then formats it into natural language (e.g., '3 days ago' or 'in 5 months') using the browser's native Intl.RelativeTimeFormat API.