The technical term is “Leap Month”
So I am guessing that Google needs some help in their development and/or QA departments. Or else Google knows something that the rest of us don’t know…
I saw this little nugget tweeted about this morning and had to try it for myself. Sure enough, my Galaxy Nexus 7 with Jelly Bean 4.2 is missing the entire month of December. (To reproduce, go into the People app, edit a contact, tap ‘Add another field’, select ‘Events’, and notice that December is not in the month scrolly.)
In an unrelated story, I predict that Android 4.2.1 will be coming out very soon.
BTW, Happy 50th Birthday to Kirk Hammett, lead guitarist for Metallica.