If your desktop won’t change, there are a number of things that could be going wrong. We’ll walk you through some of the more common problems.

First, make sure The Twenty-Four Hour Movie is enabled. Open the application and verify that the “Change the desktop picture depending on the time” checkbox is checked.

Next, verify that a folder appears under the “Use the image sequence in this folder:” line. It should have the icon of a folder and it should not say “No folder selected.” If one does not appear, you must choose a folder containing the sequence of images you want to use for your desktop.

Verify that the folder you have chosen still exists and is in the same location as when you chose it. To do this, click the “Choose…” button and re-select the folder of images. If it has moved, you will give the program its new location.

Verify your time span is small enough. If, for example, you have “one year” chosen and only two images in the folder, your desktop would only change once every six months! Be sure the image sequence is set to play over an appropriate length of time.

In the Finder, open up the folder containing your images and make sure there is at least one image in that folder. The Twenty-Four Hour Movie only supports typical image formats like JPEG or PNG. If they are in a different format, try using a program like Automator to convert your images to PNG.