Unix Timestamp & Time Zone Converter
A tool that converts Unix timestamps — auto-detecting seconds, milliseconds, microseconds, or nanoseconds — to ISO 8601 and other formats, and lists the time across multiple time zones. It also converts dates back to Unix time, all within your browser.
Numbers are auto-detected as seconds, milliseconds, microseconds, or nanoseconds by digit count (up to 11 digits = seconds, 12–14 = milliseconds). Date strings such as ISO 8601 are also accepted.
Enter a timestamp or date to see the conversions here.
Enter a valid timestamp to see the date and time in each time zone.
How to use
- Enter a Unix time (e.g. 1700000000) or a date string (e.g. 2026-09-23T12:00:00+09:00) under "Timestamp or date". Units are auto-detected from the number of digits, but you can also choose one explicitly.
- On the right, you'll see Unix time (seconds and milliseconds), ISO 8601 (UTC and your device's time zone), the HTTP date format, and the time relative to now. Copy any value with its copy button.
- "Time in each time zone" shows the date, time, and UTC offset in several time zones at once. Search to add time zones, or remove ones you don't need.
- "Convert a date to Unix time" calculates the Unix time for a date and time in the time zone you choose.
About this tool
A Unix timestamp (Unix time) represents a moment as the number of seconds elapsed since 00:00:00 UTC on January 1, 1970, and it's widely used in logs, databases, and API responses. Because languages and systems use different units — seconds, milliseconds, microseconds, or nanoseconds — this tool detects the unit automatically from the number of digits.
Time zone conversion uses your browser's built-in Intl API, which accounts for daylight saving time when calculating each region's offset from UTC. It's handy when coordinating with overseas teams or reading UTC logs in local time.
The timestamps and dates you enter are never sent to a server — all conversion happens in your browser. The current time and your local time zone are read from your device settings.
Frequently asked questions
How are seconds and milliseconds told apart?
By the number of integer digits: up to 11 digits is treated as seconds, 12–14 as milliseconds, 15–17 as microseconds, and 18 or more as nanoseconds. If the detection isn't what you intended, choose the unit manually.
Is daylight saving time taken into account?
Yes. The offset for each time zone at the given moment is calculated using the time zone database built into your browser.
Can I convert negative timestamps (before 1970)?
Yes. Enter it with a minus sign, like "-86400".
Are the values I enter sent to a server?
No. All conversion is done with JavaScript in your browser.