You can use setRepeating(..)
– which is described in detail here.
If you want to repeat the alarm in an interval that is not provided in the available constants just calculate the correct amount of milliseconds (e.g. for a week: 1000 * 60 * 60 * 24 * 7 (1 sec * 60 -> 1 min * 60 -> 1 hour * 24 -> 1 day * 7 -> 1 week)
solved Advanced AlarmManager situation [closed]