[wlesieutre]

On Android it varies a lot by manufacturer, you can find some comparisons, detailed information, and instructions to circumvent when possible here:

https://dontkillmyapp.com/

> UPDATE: We record significantly increased number of app killing on Samsung's Android Pie flavor. The hints show adaptive battery being much more eager than in stock Android.

> After 3 days any unused app will not be able to start from background (e.g. alarms will not work anymore). Imagine, you won't use your alarm clock for a the weekend +1 day and bang! no alarms any more and you miss work! We strongly suggest to turn off Adaptive battery and Put apps to sleep options per instructions below.

[kalium-xyz]

That alarm thing has happened to me several times and is why I recommend to people to not use their phone as alarm at as a dedicated device makes much more sense.