public void selectTasksForDate() {

        calendarTasks = new ArrayList<TaskEventBean>();
        Map<Task, String> calendarTasksMap = new TreeMap<Task, String>();
        DateFormat df = new SimpleDateFormat("dd-MM-yyyy");

        for (Object task : tasks) {
            for (TaskEvent activity : ((Task) task).getActivities()) {
                if (df.format(activity.getDate()).equals(df.format(selectionDate))) {
                    calendarTasksMap.put((Task) task,
                            calendarTasksMap.containsKey(task) ? calendarTasksMap.get(task) + " > " + activity.getName() : activity.getName());
                }
            }
        }

        for (Object task : closedTasks) {
            for (TaskEvent activity : ((Task) task).getActivities()) {

                if (df.format(activity.getDate()).equals(df.format(selectionDate))) {
                    calendarTasksMap.put((Task) task,
                            calendarTasksMap.containsKey(task) ? calendarTasksMap.get(task) + " > " + activity.getName() : activity.getName());
                }
            }
        }

        for (Task task : calendarTasksMap.keySet()) {
            calendarTasks.add(new TaskEventBean(task, calendarTasksMap.get(task)));
        }
        setChanged();
    	notifyObservers(null);
    }