Phil’s suggestion is a great one – there’s no other built in means of doing this (though as ever we welcome any feature requests you might post).
If you are at home doing some custom development work you might look at this tutorial and see if it gives you some ideas/code you can repurpose: I would say immediately though it is in need of an update and also relates to the calendar widget rather than month view itself – but a number of the ideas it implements could certainly be abstracted out and reused.
Hope that helps – and please do post a feature request/add your support to any suitable existing requests 🙂
Cheers!