If your post-titles needs to be filtered (i.e. you're using polyglot for multilingual wordpress blogs), the filter won't be applied for the calendar post titles.
I suggest to insert this in line #564 in file
$ak_titles_for_day[$day] = apply_filters('the_title', $ak_titles_for_day[$day]);
Thus any filter applied for the post title will be also applied on the calendar.