How to cancel a repeating notification on a particular date

Question

Well I have tried enough to look for the answer to the question mentioned above, but my efforts have been futile so far. I have created an alarm with the help of the alarmmanager class which will fire up the notification at regular intervals of time(probably about 5 days). Below is the code for the implementation of the alarm happening inside onClick() of a button.

AlarmManager alarmManager = (AlarmManager) getSystemService(Context.ALARM_SERVICE);

    Intent notificationIntent = new Intent("android.media.action.DISPLAY_NOTIFICATION");
    notificationIntent.addCategory("android.intent.category.DEFAULT");

    PendingIntent broadcast = PendingIntent.getBroadcast(this, 100, notificationIntent, PendingIntent.FLAG_UPDATE_CURRENT);

    Calendar cal = Calendar.getInstance();
    if(fromDateEtxt.getText().toString().length()>0) {
        cal.add(Calendar.HOUR_OF_DAY, 10);
        alarmManager.setRepeating(AlarmManager.RTC_WAKEUP,cal.getTimeInMillis(), 5 * 24 * 60 * 60 * 1000, broadcast);

    }

The code for the broadcast receiver.

public class AlarmReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
    Intent notificationIntent = new Intent(context, NotificationActivity.class);

    TaskStackBuilder stackBuilder = TaskStackBuilder.create(context);
    stackBuilder.addParentStack(NotificationActivity.class);
    stackBuilder.addNextIntent(notificationIntent);

    PendingIntent pendingIntent = stackBuilder.getPendingIntent(0, PendingIntent.FLAG_UPDATE_CURRENT);

    NotificationCompat.Builder builder = new NotificationCompat.Builder(context);

    Notification notification = builder.setContentTitle("Demo App Notification")
            .setContentText("New Notification From Demo App..")
            .setTicker("New Message Alert!")
            .setSmallIcon(R.mipmap.ic_launcher)
            .setContentIntent(pendingIntent).build();

    NotificationManager notificationManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
    notificationManager.notify(0, notification);
}}

The onClick() method apart from starting of the alarm changes the activity also. Now the problem I am facing is I dont know really how to stop the repeating alarm. I want to stop the alarm on a particular date. Secondly, I was confused whether to use the alarm.cancel for cancelling the alarm or to use another alarm for cancellation of the previous alarm as shown here. Apart from this, I wanted to know if the alarm could be cancelled from another activity or does the point seems unnecessary and the limit to the date could be set beforehand?