Android : Set multiple alarms sequentially

I want to set 2 alarms but only one is set! If I insert sleep between setting alarms it will works! does any one knows why it operates like this?

    Intent alarmIntent = new Intent(AlarmClock.ACTION_SET_ALARM);
    alarmIntent.putExtra(AlarmClock.EXTRA_MESSAGE, "Alarm1");
    alarmIntent.putExtra(AlarmClock.EXTRA_HOUR, 17);
    alarmIntent.putExtra(AlarmClock.EXTRA_MINUTES, 0);
    alarmIntent.putExtra(AlarmClock.EXTRA_SKIP_UI, true);
    alarmIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    context.startActivity(alarmIntent);

      try {
          Thread.sleep(10000);
      } catch (InterruptedException e) {
          e.printStackTrace();
      } 


    Intent alarmIntent2 = new Intent(AlarmClock.ACTION_SET_ALARM);
    alarmIntent2.putExtra(AlarmClock.EXTRA_MESSAGE, "Alarm2");
    alarmIntent2.putExtra(AlarmClock.EXTRA_HOUR, 18);
    alarmIntent2.putExtra(AlarmClock.EXTRA_MINUTES, 0);
    alarmIntent2.putExtra(AlarmClock.EXTRA_SKIP_UI, true);
    alarmIntent2.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    context.startActivity(alarmIntent2);