On some Android versions, this option may be named Lock screen and security.
You can choose to display a Clock, Calendar, or Image on your screen display.
If you select Calendar, you’ll see a monthly calendar on your standby display. You can also tap Image here to select an image to display on your screen without a clock.
You can select a layout with a digital clock, analog clock, world clock or edge clock.
Some analog clocks will also allow you to select a picture from your Android’s gallery and use in the background.