If you're looking for an easy way to automatically change your Windows 10 wallpaper based on specific times of the day, then you'll need a third-party program like Wallpaper Change Scheduler by FutureSight Technologies.
As you may know, Windows 10 (as well as Windows 7 and Windows 8) support automatic wallpaper change, but the desktop slideshow function cannot change the wallpaper based on the time of day. It can only change wallpapers at selected intervals, such as every minute, hour, etc. And even though you set it to change wallpaper every hour, it doesn't work if you turn off your computer.
Something similar to the request exists in the Mojave version of Apple's macOS, where it has integrated a new function with the name Dynamic desktop, which allows you to automatically change the desktop wallpaper according to the time of day. But, let's go back to Windows.
Change the Windows 10 desktop based on the time of day
The Wallpaper Change Scheduler is a free program designed to allow users of Window 10, Window 8 and Window 7 to automatically change wallpaper based on time of day, daily or weekly. That is, you can have a new wallpaper for any particular time of day!
Setting up the program is quite easy. After downloading and running the program, you just have to click on the "Add Event" button. Select the “Trigger” box as “Daily”, select the time at which you want your wallpaper to change or rotate, and then select the wallpaper you want to view at the selected time. Click the “Create” button.
If you want to change the wallpaper based on the time of day, you need to add a wallpaper for each hour of the day you want to change. That is, if you want to change every hour, you have to create a total of twenty-four events (one event per hour) with twenty-four different wallpapers.
The program was originally designed for Window 7 and has not been updated for a long time. However, it is fully compatible with Window 10 and works fine.
You can download it Wallpaper Change Scheduler from here.
