Timestamp Converter
Convert between Unix timestamps, ISO 8601, and human-readable dates with timezone comparison and auto-detection.
— — — — — ————— — — — | City | Date & Time | Zone |
|---|
About This Tool
Convert between Unix timestamps and human-readable date formats. The tool supports bidirectional sync, automatic detection of seconds vs milliseconds, and comparison across 11 timezones simultaneously.
Features
Bidirectional sync — timestamp and date picker stay synchronized; editing either updates all outputs instantly
Auto-detect seconds / milliseconds — automatically determines the unit based on digit count, with manual override
Multiple output formats — Local time, UTC (ISO 8601), RFC 2822, short date (YYYY-MM-DD), week number, and day of year
Timezone comparison — view the same moment across 11 cities (New York, Los Angeles, Chicago, London, Berlin, Tokyo, Shanghai, Kolkata, Sydney) with your local timezone highlighted
Live clock — current Unix timestamp updates every second with a “Now” button to instantly capture it
Relative time — human-readable “time ago / from now” display that refreshes automatically
Shareable links — timestamps are encoded in the URL (
?ts=…&unit=…) for easy sharingCopy buttons — one-click copy on every output value
How to Use
Enter a Unix timestamp to see date, timezone table, and all formats update instantly
Or pick a date and time — the timestamp input and all outputs sync automatically
Click Now to capture the current timestamp
Use the Auto / Seconds / Milliseconds toggle to control unit interpretation (Auto uses digit count heuristic: ≤10 digits → seconds, >10 digits → milliseconds)
Click Share Link to copy a URL that opens the tool with the same timestamp pre-filled
Auto-Detection Logic
When the unit selector is set to Auto (default), the tool determines the unit based on the input magnitude:
≤ 9,999,999,999 (10 digits or fewer) → interpreted as seconds. This covers dates up to November 2286.
> 9,999,999,999 (11+ digits) → interpreted as milliseconds. JavaScript’s
Date.now()returns 13-digit millisecond timestamps.
You can always override the auto-detection by selecting Seconds or Milliseconds manually.
Output Formats Reference
Local Time — formatted using your browser’s locale and timezone (
toLocaleString())UTC (ISO 8601) —
2025-01-15T10:30:00.000Z— the standard for APIs, logs, and data interchangeRFC 2822 —
Wed, 15 Jan 2025 11:30:00 +0100— used in email headers and HTTP datesShort Date —
2025-01-15— ISO 8601 date-only formatWeek Number — ISO 8601 week number (W01–W53), useful for sprint planning and reporting
Day of Year — ordinal day (1–366) with total days in the year, useful for Julian date references
Notable Unix Timestamps
| Timestamp | Date (UTC) | Event |
|---|---|---|
0 | 1970-01-01 00:00:00 | Unix Epoch — the origin of Unix time |
1000000000 | 2001-09-09 01:46:40 | One billion seconds since epoch |
1234567890 | 2009-02-13 23:31:30 | Sequential digits — celebrated by developers worldwide |
2000000000 | 2033-05-18 03:33:20 | Two billion seconds since epoch |
2147483647 | 2038-01-19 03:14:07 | Y2K38 — 32-bit signed integer overflow. Systems storing timestamps as |
4294967295 | 2106-02-07 06:28:15 | 32-bit unsigned integer maximum |
Linux Command Reference
Common timestamp operations from the terminal:
Get Current Timestamp
Timestamp to Date
Date to Timestamp
Convert Between Timezones
Milliseconds Timestamp
ISO 8601 and RFC 2822
Privacy
All conversions happen entirely in your browser using JavaScript’s built-in Date and Intl APIs. No timestamp data is transmitted to any server. The shareable link only encodes the timestamp in URL parameters.