im looking for a alternative to java.util.TimerTask.
My app should start random notifications over a month.
The TimerTask can only handle one, after that it doesnt work anymore.
Does it need to get called from a backgroundService? Or is something like AlarmManager enough?
You need to use AlarmManager for scheduling tasks in this time range. There is an official training doc in the Android documentation that you might find interesting: https://developer.android.com/training/scheduling/alarms.html
Another possibility for scheduling tasks with longer periods is JobScheduler, though that's more tailored for scheduling network jobs.