My tablet runs Android 4.0.3. The stock calendar app complains that there's no calendar available, however I'm pretty sure that my calendar exists because I can read it online through other devices. I can even sync it with my Windows phone. Moreover, I don't see any button to create a new calendar. In my settings, sync calendar is enabled, and there is no problem with my Google account; I can successfully use Gmail and Play. I must be missing something... without any calendar, the calendar app is useless, uh?