Timestamp Converter
Convert Unix timestamps to human dates and back. Supports seconds and milliseconds. Shows local time and UTC ISO 8601 — entirely in your browser.
Unix timestamp → human date
Local time2025年5月29日星期四 GMT+7 07:00:00
UTC ISO 86012025-05-29T00:00:00.000Z
Human date → Unix timestamp
Unix (seconds)1780169460
Unix (milliseconds)1780169460000
All timestamp conversions happen entirely in your browser — no data is ever sent to any server. Times are shown in your local timezone.
How it works
- Unix → Date: Enter a Unix timestamp and choose whether it is in seconds or milliseconds. The tool shows the equivalent local time and UTC ISO 8601 string.
- Date → Unix: Pick a date and time using the datetime picker, or click Now to capture the current moment. The tool shows the Unix timestamp in both seconds and milliseconds.
- Copy any result with its adjacent copy button.
Frequently asked questions
- What is a Unix timestamp?
- A Unix timestamp is the number of seconds (or milliseconds) that have elapsed since January 1, 1970 00:00:00 UTC — known as the Unix epoch. It is the most common way to represent time in programming and databases.
- Should I use seconds or milliseconds?
- Most Unix timestamps in systems like databases, server logs, and POSIX APIs use seconds. JavaScript's Date.now() and many web APIs use milliseconds. If your timestamp has 13 digits it is almost certainly milliseconds; 10 digits means seconds.
- What is the 'Now' button?
- The Now button captures the current date and time at the moment you click it and fills in the date input. The resulting Unix timestamps are calculated from that moment.
- What timezone is used?
- The date input uses your local timezone (as reported by the browser). The 'Unix → Date' panel shows both local time (with timezone abbreviation) and UTC ISO 8601.
- What is ISO 8601?
- ISO 8601 is an international standard for representing dates and times. A UTC ISO 8601 string looks like 2025-05-29T14:30:00.000Z — the Z suffix means UTC. It is the format returned by JavaScript's Date.toISOString().