The extension alters the timezone information that the browser reveals to web pages to protect your actual timezone from being identified. You can ensure the extension spoofs the correct timezone by setting your preferred one on the options page. Additionally, there is an option to generate random timezones, which can be useful in preventing fingerprinting scripts from identifying your browser based on your actual time zone.

To test the current timezone use the right-click context menu item. 

The extension can also automatically detect your timezone based on your IP address starting from version 0.1.4. Use the right-click action button's menu to access this option.

Moreover, there is an option to check and update the timezone on start-up, which can be enabled from the options page.

The latest version of the extension includes improvements such as faster injection into iframes and automatic timezone detection that now respects daylight shifting. This extension now works on manifest v3.