Birthday views

Issue Summary

I'm using the most excellent Calendar + Date (specifically: Date Views) + Date iCal combo. Overall, it works very well.

I use it for my table tennis club: http://ttkherckenrode.be/club/kalender.

Now I also want to create a birthday calendar for all members. They've entered their exact birth *date*, e.g. Jan 20, 1988. The problem is then: how to display birthdays in calendars? I've traced this down to date_views_argument_handler_simple. The "month" granularity there is really "month in year" (the same applies to all other granularities). So I started adding "month (any year). But I got stuck in several places. Most importantly: the query is returning the correct results, but nothing is being rendered. I suspect this is happening because the results still refer to the year of the actual birth date?

So I figured I'd post the most simple version of what I currently have and ask for feedback. How can I work around this? Does this stand any chance of getting committed to this module? Is it even possible to move this into a module that neatly integrates with what Date Views already provides?