Be sure to heed the warning that as of V4.5, Calvetica requires iOS6 or later. Thats too bad. Im still on iOS5, for a number of reasons (Maps, Podcasts, impaired performance on my older iDevices).
I really liked Calvetica, and am saddened that those who wear the Mysterious Trousers couldnt find a way to maintain backwards compatibility with iOS5. Or perhaps the structure of Apples APIs wouldnt let them.
zeus eurynome about Calvetica Calendar, v4.5