Dynamic Wallpaper is one of the most interesting features in Mojave macOS. She changes the picture to your desktop depending on the time of day. And it can be transferred to any version of macOS.
Dynamic Wallpaper is a collection of several images that were shot at different times of the day. If you want you can create your own collection of such pictures. They should be sorted in display order, for example, they can be called file1, file2, file 3 etc. To achieve the most realistic effect, you will need from 10 to 25 images.
How to activate the dynamic Wallpaper on any version of macOS
On the website a lot of free Unsplash photos in good quality. You can download one of the pictures, make a few copies, and then change the brightness, hue and exposure, to keep the same scene, yet the atmosphere was changing.