What is the ISO 8601 format?

ISO 8601 is a standard date format like 2026-08-18T09:30:00.000Z, widely used in APIs and databases because it is unambiguous.

What time zones does it show?

It shows the date in UTC, your local time zone and ISO 8601, so you can use whichever you need.

Developer Tools

Unix Timestamp Converter

Convert Unix timestamps to dates and back, in seconds or milliseconds.

Free browser toolRuns in your browserNo sign-up

Epoch conversion workspace

Translate Unix timestamps and calendar dates in both directions

Detect second or millisecond epochs, inspect UTC/local/ISO output and generate copy-ready timestamps from a local date-time.

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timestamp

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date input

Local + UTC

zone

Timestamp to date

Seconds or milliseconds

Seconds or milliseconds are both detected automatically.

Date to timestamp

Local date-time input

A datetime-local value has no embedded time-zone offset, so the browser interprets it in your current local time zone before producing UTC epoch values.

Private by design. Input is processed inside this browser tab and is not sent to ToolsOnDuty.

About the Unix Timestamp Converter

A Unix timestamp counts the seconds since 1 January 1970 (UTC), a simple way for computers to store a moment in time.

This tool converts a timestamp into a readable date in UTC, local and ISO 8601 formats, and converts a date back into a Unix timestamp in seconds and milliseconds.

It automatically detects whether your timestamp is in seconds or milliseconds, and everything runs in your browser.

Key features

Timestamp to UTC, local and ISO date
Date to Unix seconds and milliseconds
Auto-detects seconds vs milliseconds
One-click 'Now' button

How to use

1Enter a timestamp to see the matching date, or click Now.
2Or pick a date and time to get its Unix timestamp.
3Copy the value you need.

Examples

Epoch to date

Input: 0

Output: 1970-01-01 00:00:00 UTC

Epoch time counts seconds since 1 January 1970 UTC.

Date to epoch

Input: 2000-01-01 00:00:00 UTC

Output: 946684800

A calendar date is converted back to seconds since the epoch.

Frequently asked questions

Seconds or milliseconds?: Both work. The tool treats 13-digit numbers as milliseconds and shorter numbers as seconds, and shows both when converting a date.
What is the ISO 8601 format?: ISO 8601 is a standard date format like 2026-08-18T09:30:00.000Z, widely used in APIs and databases because it is unambiguous.
What time zones does it show?: It shows the date in UTC, your local time zone and ISO 8601, so you can use whichever you need.

Open a related tool to prepare your files or refine the finished result.