Timestamp Converter

When this tool helps

Compare API timestamps, device logs, and cached-record expiration times. This is especially useful when one mobile SDK reports milliseconds and your backend reports seconds.

How to use this tool

Unix time counts elapsed time from 1970-01-01T00:00:00Z. Select the correct unit: seconds and milliseconds differ by a factor of 1,000. ISO input must include a timezone to avoid ambiguity.

A worked example

Input

1767225600 (select Seconds)
1767225600000 (select Milliseconds)
2026-01-01T05:30:00+05:30

Expected result

All three represent:
UTC: 2026-01-01T00:00:00.000Z
Unix seconds: 1767225600
Milliseconds: 1767225600000

Run each input separately. The Local line reflects the browser timezone and will differ between users. The unit selector applies to numeric input; an ISO string carries its own offset. Z means UTC.

Edge cases and limitations

• A date around January 1970 often means seconds were interpreted as milliseconds. Check the API contract before changing the number.
• ISO input must include a timezone. A timezone-free appointment is a different requirement from a fixed instant.
• The converter uses JavaScript Date parsing; it is not a strict calendar-date validator. Check invalid calendar dates separately in application input validation.

Use the result in your app

For a Flutter DateTime or Android Instant, preserve the same instant through parsing and formatting. Test a timezone offset and a daylight-saving boundary if your feature uses local calendar times.

Keep your workflow private

This utility processes input only in this tab. It does not upload or persist pasted content. Review generated output before using it in a production application.