How to customise Always On Display in Samsung Galaxy S8+?

Select a clock, calendar, or picture to display so you don't need to turn on the screen when your device has been idle and the screen timeout turns on.

Swipe up to access Home screen → Settings → Lock screen and security → Always on display → Analog clock → Clock style → Color → Background → APPLY  

Pictorial representation of the above settings are as follows :  

1. From a Home screen, swipe up or down to access the Apps screen.

2. Touch Settings.

3. Touch Lock screen and security.

4. Touch Always On Display.

NOTE : Always On Display is enabled by default. To disable Always On Display, touch the slider.

5. Select the desired clock style. For this example, touch Analog clock.

6. To change the clock style, touch Clock style and then select the desired clock style.

7. To change the color, touch Color and then select the desired color.

8. To change the background, touch Background and then select the desired background.

9. To apply the changes, touch APPLY.

CLICK HERE to know how to add or remove a Widget from a Home screen in Samsung Galaxy S8+ ( SM-G955 ).