Calendar: repeating events

I entered an all-day event on Thursday, 27 March, 2014, and set 'Repeat' to 'Every day', finishing on Monday, 31 March. Bizarrely, it appeared in Calendar on 27, 28, 29 and 31 March, but not on Sunday, 30 March.

I then tried again, entering the event not as 'all day' but at 9 am. It appeared at 9 am on 27, 28, 29 and 31 March, but (even more bizarrely) at 10 am on Sunday, 31 March.

Finally, I tried it as 'all day' once more, but did the settings in some other order (and, unfortunayely, cannot any more remember what order). This time it appeared once on 27 March, twice on 28 March, three times on 29 March, four times on 30 March — yes, on Sunday, 30 March! — and five times on 31 March.

Am I going mad, or is Calendar going mad? I do not believe that Calendar's bizarre behaviour has anything to do with observing the Sabbath, for previously I had entered an all-day event, repeating daily over several weeks (but not including March, 2014), and there were no Sabbath-observance omissions. So what is it with Sunday, 30 March, 2014?

PS: I then deleted the new event from Calendar altogether and entered it as an all-day event, repeating daily, in my iPhone. It appeared on the iPhone quite correctly on every day from 27 to 31 March, including Sunday, 30 March. But when I synced it with Calendar on my computer (using iTunes), it once again did not appear in the computer's Calendar on Sunday, 30 March.

Help!