Help with iOS Calendar Ap Crashing on iPad mini

Everything was fine... I have an original iPad mini with iOS 7.1.2. Synch calendars with my wife using iCloud. All of a sudden coincident with my wife adding an event on our shared calendar, my iPad mini open calendar and then crashed immediately. I have tried all the steps I have seen on our postings including closing ap, deleting most recent event, restart, soft reboot and even deleting all April 1 events (including US Holidays) from my iCloud calendar. None of that works. Mac iCloud calendar and 2 other iDevnces (iPad 2 and iPhone 5) work perfectly. How do I get my calendar working again on my mini???

Problem gone but mystery remains...

Thank you for the reply. I had deleted just the default calendar that has US Holidays and did not seem to do anything as of when I went to bed. This morning, 8 hours later all seems normal again. Problem gone, mystery remains...