PicWheel is a program to update desktop wallpaper as per schedule specified by user. It is simple and it is fun.

If you have many JPEG, GIF, BMP, DIB, WMF, or EMF pictures you can put them all in one list. Randomize the list or arrange it in any order you wish. Specify when you want to change the wallpaper: every 10 minutes, every hour, every day, etc. (program supports changing from in 10-second period to particular day & time schedules). While working with the list you can preview pictures and check their sizes. All pictures are automatically scaled to fit the desktop best.

PicWheel has English and Russian interfaces and supports command line.