static void show_calendar(appdata_s *ad) {

	Evas_Object *calendar = elm_calendar_add(ad->win);
	evas_object_size_hint_weight_set(calendar, EVAS_HINT_EXPAND,
	EVAS_HINT_EXPAND);
	elm_win_resize_object_add(ad->win, calendar);
	evas_object_show(calendar);

	//add a calendar mark two days ago
	struct tm selected_time;
	time_t current_time = time(NULL)-2*60*60*24;
	localtime_r(&current_time, &selected_time);
	//keep mark's reference in order to delete it with elm_calendar_mark_del(mark) function
	Elm_Calendar_Mark *mark =elm_calendar_mark_add(calendar, "checked", &selected_time, ELM_CALENDAR_MONTHLY);

	//clean all marks
	//elm_calendar_marks_clear(calendar);
	//elm_calendar_marks_draw(calendar);
	
}