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Unix Timestamp Converter

Local only

The Unix Timestamp Converter detects seconds, milliseconds, microseconds, or nanoseconds and shows the same instant in UTC and selected time zones. All conversion uses browser Date and Intl APIs.

Reviewed · Free · No account required

Timestamp Workspace

Unix timestamp to date

Auto-detect uses digit length: 10 seconds, 13 milliseconds, 16 microseconds, or 19 nanoseconds.

Date to Unix timestamp

The date input uses the browser’s local time zone. Output below shows both UTC and the selected display zone.

Converted resultWaiting for input
ISO 8601 / UTC
Selected time zone
Unix seconds
Unix milliseconds
Relative to now
Conversions use the browser Date and Intl APIs. No timestamp is transmitted.

What does the Unix Timestamp Converter do?

The KitLumi Unix Timestamp Converter maps a numeric epoch value to a real date and converts a browser-local date back to Unix seconds. The page displays UTC separately so local time-zone offsets are explicit.

How do you convert a Unix timestamp?

  1. Paste a timestamp and keep Auto-detect, or choose its exact unit.
  2. Select the time zone used for the readable display.
  3. Copy the ISO 8601, Unix seconds, or millisecond result required by your application.

How large is each Unix time unit?

UnitTypical current lengthRelation to one second
Seconds10 digits1
Milliseconds13 digits1,000
Microseconds16 digits1,000,000
Nanoseconds19 digits1,000,000,000

What can cause the wrong date?

The most common error is treating a millisecond value as seconds, which creates a date far outside the expected year. A local date can also appear shifted when one system assumes UTC and another interprets the same text without a time-zone offset.

Frequently asked questions about Timestamp Converter

How does the converter detect seconds or milliseconds?

Auto-detect uses digit length: up to 10 digits is treated as seconds, up to 13 as milliseconds, up to 16 as microseconds, and longer values as nanoseconds.

Is a Unix timestamp affected by time zones?

No. A Unix timestamp identifies an instant relative to 1970-01-01T00:00:00Z. Time zones affect only how that instant is displayed.

Why is the displayed hour different from my input?

The date input uses the browser local time zone, while ISO 8601 output is UTC. Select a display zone to compare the same instant in another region.

Does the converter account for daylight saving time?

Yes, when the browser has current IANA time-zone data. Historical and future rule accuracy depends on the browser and operating system.

What changed?

Initial release · September 24, 2026

Added automatic unit detection, bidirectional date conversion, ISO 8601 output, selected IANA time zones, and relative time.

Who maintains this tool?

KL
KitLumi EngineeringKitLumi Engineering maintains browser behavior, privacy disclosures, examples, and automated tests.