I took a look at it and I really don't think there's any way to easily achieve what you are trying to do using the OOTB calendar gadget. I see that the configuration options allow you to define a custom style sheet to associate with the calendar, so maybe there's a way to leverage that?
But I'm probably telling you something you already know. Maybe someone else in the community has a tip for building a custom one. I know from past experience though that implementing a calendar UI is a lot trickier than it would seem on the surface.
My initial recommendation would be to work with the standard OOTB functionality. At the least, I could submit an enhancement request on your behalf to potentially be considered for a future release.