In this podcast, Alex Hall gives us an introduction to using the Mac OS X Calendar with VoiceOver.
While it does not happen in this podcast, VoiceOver will sometimes skip over events in Month View. This problem only affects some users, and can often be avoided by using Week View instead. It has been reported to us that Apple is working on a fix, so be sure to keep your Mac up to date. This is as of OS X 10.10.3.