Alarm Clock can not work

[Anke]

Did you try this?

@Anke

Check it out, if the problem also occurs when the device is connected to a charging cable and charging during the test.

If this works and it doesn't work without charging, then you know for sure that Doze mode is the problem. Then use a Foreground service.

[DickLiu]

Thanks for your quickly reply! I will try what you said. And how to use a Foreground service?

[DickLiu]

How do you make an app always running?

To do this, you will need a → background service and a → foreground service (since the background service does not prevent the app from falling into Doze mode). https://ullisroboterseite.de/android-AI2-KeepAlive-en.html

[DickLiu]

I got the time format wrong. Now the alarm clock is working. I want to thank whoever replies to my question.

[Anke]

@DickLiu

time format

Yes, this was the first thing that I changed in your project (before testing):

[DickLiu]

I see and thanks for your help!