Private developer tools

Unix Timestamp Converter

Convert epoch seconds or milliseconds into ISO, UTC, and local dates—or turn a calendar time back into both Unix formats.

Private date utility

Decode a Unix timestamp

Browser local
ResultWaiting for a valid value

Converted dates and timestamps will appear here.

Choose a direction and enter a value.

How to use it

Get a reliable result

  1. Choose Timestamp to Date or Date to Timestamp.
  2. Enter an epoch value and unit, or enter a calendar date and choose UTC or your local timezone.
  3. Convert the value, verify the accompanying formats, and copy the result you need.

Useful for

Common workflows

  • Inspect timestamps from logs and API payloads
  • Create epoch values for tests and scheduled events
  • Distinguish second-based and millisecond-based timestamps

Examples

What to expect

Epoch seconds
Input
1767225600 seconds
Output
2026-01-01T00:00:00.000Z

The same instant can display as a different calendar time in the browser's local timezone.

UTC calendar date
Input
2026-01-01 00:00:00 interpreted as UTC
Output
1767225600 seconds · 1767225600000 milliseconds

Know before you start

Important limitations

  • Automatic unit detection is a magnitude-based convenience and can misclassify unusual historical or far-future timestamps; choose a unit explicitly when uncertain.
  • Local calendar conversion uses this browser's timezone database and can reject nonexistent times during daylight-saving transitions; repeated local times can remain ambiguous.
  • JavaScript dates are limited to approximately 100 million days on either side of 1970 and represent time only to millisecond precision.
  • Unix time does not encode a timezone name and does not model leap seconds.

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Common questions

Unix Timestamp Converter FAQ

What is a Unix timestamp?

It is a count of elapsed seconds or milliseconds relative to 1970-01-01 at 00:00:00 UTC. It represents an instant rather than a named timezone.

How does automatic unit detection work?

Absolute values of 100 billion or more are treated as milliseconds; smaller values are treated as seconds. Select the unit explicitly for unusual historical or far-future data.

Why do UTC and local results look different?

They show the same instant using different timezone rules. Local output follows the timezone configured in the current browser.

Are timestamps sent to a server?

No. Parsing, date formatting, timezone interpretation, and copying happen in the current browser.

Browser-local

Processed on your device

Timestamps and dates are converted locally in this browser and are never uploaded or stored.

How this processing works

The tool reads and processes this input in your browser. Tool Packer's application server does not receive the input or generated result.

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