How to fire alarms with same time and date android

Question

I have this goal setting app wherein in each activity of the goal set in the app is set with an alarm time and date.

For example:

Goal 1: A

Activity a1: nana

Deadline: 11/5/2015

Alarm Time: 9:00 am

Goal 2: B

Activity b1: hehe

Deadline: 11/5/2015

Alarm Time: 9:00 am

Only one of them is fired. I tried putting them different millisecond on each activity alarm time. But Its still the same. I want to them to be fired at the same time. I tried other sources and they suggest to use setExact() but i cant use that function cause its only for API 19 and above. My API is 17. And there's no problem when i set alarms with different time but the same date.

This is my code:

First, I put the alarm time set on an activity in the TABLE_ACTIVITIES.

public void setAlarm(){

        Activities act = dbhandler.getActivity(actid);

// give them random millisecond
        int min = 1;
        int max = 1000;

        Random r = new Random();
        m = r.nextInt(max - min + 1) + min;

        MessageTo.message(SetNotifyActivity.this,Integer.toString(m));

//the second is 0
        dbhandler.updateActivityAlarm(hour,minute,0,m,goal_id,actid);


    }

and then setting all the alarms in all activities the user made in each goal

public void setAlarms(){
        List<Activities> allActs = dbhandler.getAllActivitiesByGoal(goal_id);

        for (final Activities act : allActs) {

            //for alarm
            //Create an offset from the current time in which the alarm will go off.

            Calendar cal = Calendar.getInstance();
            cal.setTimeInMillis(System.currentTimeMillis());
            cal.set(Calendar.DATE, Integer.parseInt(act.getEDay()));  //1-31
            cal.set(Calendar.MONTH, Integer.parseInt(act.getEMonth()) - 1);  //first month is 0!!! January is zero!!!
            cal.set(Calendar.YEAR, Integer.parseInt(act.getEYear()));//year...

            cal.set(Calendar.HOUR_OF_DAY, act.getHour());
            cal.set(Calendar.MINUTE, act.getMinute());
            cal.set(Calendar.SECOND, 0);
            cal.set(Calendar.MILLISECOND, act.getMillisecond());
            //MessageTo.message(SetNotifyActivity.this, hour+":"+minute+" "+format);

            //assigned a unique id to notifications


            //Create a new PendingIntent and add it to the AlarmManager
            Intent intent3 = new Intent(this, ViewTasksActivity.class);
            intent3.putExtra("goalid", Integer.toString(goal_id));
            intent3.putExtra("activityId", Integer.toString(act.getActId()));
            intent3.putExtra("activityName", act.getActivityName());
            intent3.putExtra("show", "true");
            PendingIntent pendingIntent = PendingIntent.getActivity(this,
                    act.getActId(), intent3, PendingIntent.FLAG_CANCEL_CURRENT);
            AlarmManager am =
                    (AlarmManager) getSystemService(Activity.ALARM_SERVICE);


            am.set(AlarmManager.RTC_WAKEUP, cal.getTimeInMillis(),
                    pendingIntent);
        }
    }