A fully fledged calendar function including custom calendars will
soon(TM) be implemented. I.e. we have been waiting for improvements of this feature since the beginning of time. Many things are already prepared in the code, but - as far as I know - the GUI has to be completely overhauled. As we have been told, a programmer will have to work at least a complete month on it. Since RW understandably needs the revenue, the calendar features will have to wait until after the opening of the content market.
So, all we can do is wait more or less patiently, remined the good folks at Lone Wolf of our needs regularly, and hope.