Timestamp Converter

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 sharing

• Copy buttons — one-click copy on every output value

How to Use

1. Enter a Unix timestamp to see date, timezone table, and all formats update instantly

2. Or pick a date and time — the timestamp input and all outputs sync automatically

3. Click Now to capture the current timestamp

4. Use the Auto / Seconds / Milliseconds toggle to control unit interpretation (Auto uses digit count heuristic: ≤10 digits → seconds, >10 digits → milliseconds)

5. 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 interchange

• RFC 2822 — Wed, 15 Jan 2025 11:30:00 +0100— used in email headers and HTTP dates

• Short Date — 2025-01-15 — ISO 8601 date-only format

• Week 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

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.

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