How do you make a video on iMovie longer than 30 minutes?

To create a video longer than 30 minutes in iMovie, ensure you're using iMovie on macOS, as the mobile version has a 30-minute limit. Start by creating a new project and import your media. You can then add clips to the timeline, and there is no set time limit for the total duration, allowing you to extend your video as needed. Once finished, export your project by selecting "File" > "Share" to save it in your desired format.