Its very easy to automate wallpaper changes using "CLARO : Wallpaper Changer".
✔ Create multiple folders with set of images from gallery,
✔ Choose days and time to set the random wallpapers from folder,
✔ Set interval time, how often you want to change the wallpaper.
all done !!

[More Options]
✔ Choose Color Filters for wallpapers: Sepia, Grayscale, Blur, Random
✔ Schedule wallpaper changes as per your need: Select Days, Time Range, Interval
✔ Choose Image Order: Random or sequence
✔ Complete control over Notification alerts: Enable/Disable Notification, notification tone, vibrate, Phone wakeup
✔ Wallpaper Picker: Auto apply wallpaper changes or enable Wallpaper picker on schedule time.
✔ Dark Theme: Material Design with Dark/Light Themes.
✔ Blur Wallpaper

CLARO is not a Live Wallpaper, its App without any background services and hence its very battery friendly.

If you like CLARO : Random Wallpaper changer don't forget rate 5 star ★★★★★ or review or can unlock app