title: How to save an entry after changing date in QCalendarWidget?
body: <p>I want to choose a day at a QCalendarWidget and save text for this particular day in a database. Now I'm looking for a good save-strategy. At the moment I'm using the <code>QTextEdit::textChanged()</code>-Signal, but of course this has very bad performance. Best choice would be to save after changing the day in the calendar or when the program closes. But how can I realize that?</p>