private void setAlarm(long timeInMillis) {
        AlarmManager alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
        Intent intent = new Intent(this, MyAlarm.class);
        PendingIntent pendingIntent = PendingIntent.getBroadcast(this, 0,intent,0);
        alarmManager.setRepeating(AlarmManager.RTC_WAKEUP, timeInMillis, AlarmManager.INTERVAL_DAY,pendingIntent);
    }
...
public class MyAlarm extends BroadcastReceiver{
    @Override
    public void onReceive(Context context, Intent intent) {
        Toast.makeText(context, "Бах!", Toast.LENGTH_SHORT).show();
    }

}