Here you can choose after which time the continous alarm should stop. This is really useful if you forgot your device at home and it rings constantly, annoying your neighbours.

Android 9
Step 1:  Tap on  Clock
Step 2:  Open the  menu
Step 3:  Open the  settings
Step 4:  Tap on  Silence after
Step 5:  Choose an  option 
  1. Tap on Clock
  2. Open the menu
  3. Open the settings
  4. Tap on Silence after
  5. Choose an option 

Android Instructions
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