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Unix Timestamp Converter — Usage guide

Convert Unix timestamps and ISO dates with seconds or milliseconds selected explicitly. Display results in UTC and a chosen time zone.

How to use it

  1. Explicitly choose seconds or milliseconds.
  2. Convert a timestamp to a date or enter a date to create a timestamp.
  3. Review UTC and selected-zone values, then copy what you need.

Input and output examples

Example 1

Input

0 seconds

Output

1970-01-01T00:00:00.000Z

Example 2

Input

1735689600000 milliseconds

Output

2025-01-01T00:00:00.000Z

Frequently asked questions

Are 13-digit numbers automatically milliseconds?

No. You select the unit. A 13-digit number is interpreted as seconds if you choose seconds.

Is zero a valid timestamp?

Yes. Zero seconds is 1970-01-01T00:00:00Z.

Does the selected time zone change the timestamp?

The UTC instant stays the same; only the displayed local date and time change with the selected zone.

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