I had the same issue and i found two solutions:
1. Show free time in agenda view (i did not like it)
2. Opened the recurring all day event that the Agenda kept jumping to (it was a repeating b-day) and i made it a timed appointment for one hour on that day.
For now i am sticking with #2 until i find something better, even thou mom now gets to celebrate her b-day for one hour