Data tools

Unix Timestamp Converter

Convert seconds, milliseconds, and microseconds between Unix timestamps and dates.

Processed locally in your browser. Your input is not uploaded to our server.

Browser timezone: UTC

Convert a value, or request the current timestamp.

Conversion output

No conversion yet.

How to use Timestamp Converter

  1. Choose timestamp-to-date, date-to-timestamp, or current-time mode.
  2. Enter the value and select units plus UTC or browser-local interpretation where applicable.
  3. Compare UTC, local, and epoch outputs, noting timezone and precision labels before copying.

Supported behavior

Unix Timestamp Converter moves between epoch values and human-readable dates in three modes: timestamp to date, date to timestamp, and current timestamp. Values can be seconds, milliseconds, microseconds, or auto-detected. Results include ISO 8601 and RFC 3339 UTC text, the browser’s local date and timezone identifier, Unix values in all three units, day of week, and relative time from now. Date entry accepts seconds and milliseconds and can be interpreted explicitly as UTC or browser-local time. Negative timestamps work within JavaScript’s supported Date range; out-of-range values report an error. Microseconds beyond millisecond precision are retained numerically and labeled because JavaScript Date cannot represent the final three digits. Current time changes only on request or once per second in live mode. All entered dates and calculated values stay in your browser and are never uploaded. Relative time and local display depend on the current clock and timezone, while UTC conversion is deterministic for a given epoch.

  • JavaScript Date represents milliseconds, so finer microsecond digits are retained separately rather than as Date precision.
  • Relative time and browser-local output vary with the device clock and selected timezone environment.

Examples

                0 seconds

Result: 1970-01-01T00:00:00.000Z; Thursday; 0 ms; 0 µs

                -1 seconds

Result: 1969-12-31T23:59:59.000Z; -1000 ms; -1000000 µs

Common use cases

  • Translate an epoch value from a log into an ISO UTC date.
  • Create seconds and milliseconds for a scheduled test fixture.
  • Check how one instant appears in the browser’s local timezone.

Frequently asked questions

What does timestamp zero represent?

It is 1970-01-01T00:00:00.000Z in UTC.

Are negative timestamps allowed?

Yes, provided the resulting date lies within JavaScript’s supported range.

How are seconds and milliseconds distinguished?

Select the unit explicitly or use auto-detection, then verify the displayed conversions.

Are all six microsecond digits shown accurately as a Date?

The numeric timestamp is retained, but precision beyond milliseconds is labeled as not representable by JavaScript Date.