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Timestamp converter

Convert between Unix timestamps (seconds or milliseconds) and human-readable ISO 8601 dates. View timestamps in UTC and your resolved local timezone, with a live ticker and one-click 'Now' button. Runs entirely client-side.

Current Unix time:1793694449

Enter seconds (e.g. 1725485580) or milliseconds (e.g. 1725485580000)

Conversion result2 years ago
1725485580
1725485580000
2024-09-04T21:33:00.000Z
Wed, 04 Sep 2024 21:33:00 GMT
Wednesday, September 4, 2024 at 9:33:00 PM UTC
Day of week
Wednesday
Day of year
Day 248 of 365/366
Resolved timezone
UTC

Timestamp converter example

Epoch timestamp to UTC and local time

Timestamp 1725485580 becomes 2024-09-04T21:33:00.000Z in UTC, along with formatted local time, relative difference, and millisecond representation 1725485580000.

Timestamp converter how-to

  1. If input is numeric: parse as number. If auto-detect, values with absolute value >= 1e11 are milliseconds; otherwise multiply by 1000 to get milliseconds. Create `new Date(ms)`.
  2. If input is a date string: parse with `new Date(string)`. Validate `!isNaN(date.getTime())` and year between 0001 and 9999.
  3. Derive unixMillis = date.getTime(), unixSeconds = Math.floor(unixMillis / 1000).
  4. Format isoUtc = date.toISOString(), utcString = date.toUTCString().
  5. Format localString using Intl.DateTimeFormat with user's local timezone (or specified timezone).
  6. Compute relative offset from Date.now() using Intl.RelativeTimeFormat.

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Timestamp converter FAQ

What is a Unix timestamp?
A Unix timestamp (epoch time) counts the number of seconds that have passed since January 1, 1970 00:00:00 UTC, excluding leap seconds. Millisecond timestamps multiply this count by 1,000.
How does the tool distinguish seconds from milliseconds?
In auto mode, timestamps with 11 or more digits (like 1725485580000) are treated as milliseconds, while 10-digit values (like 1725485580) are treated as seconds. You can also explicitly toggle between Seconds and Milliseconds.
Are timezone conversions accurate?
Yes. UTC time is computed directly from the epoch value. Local time uses your browser’s Intl.DateTimeFormat API with your operating system’s resolved timezone.
Does this converter send timestamps to a server?
No. Conversion happens entirely in JavaScript in your browser using standard Date and Intl APIs. Nothing leaves the tab.
What formats can I convert from?
You can enter epoch seconds, epoch milliseconds, ISO 8601 strings (e.g. 2026-09-04T21:33:00Z), or standard date strings. The tool bidirectionally converts between epoch numbers and calendar dates.
How do I convert timestamps without this page?
To date: if input is in seconds, ms = sec * 1000; date = new Date(ms). date.toISOString() yields UTC ISO 8601; date.toUTCString() yields RFC 2822 format; Intl.DateTimeFormat yields local representation. To timestamp: date = new Date(isoString); unixSeconds = Math.floor(date.getTime() / 1000); unixMillis = date.getTime().