It came from Outlook users but we’ve found out it’s indeed a real issue. For example assume it is Thursday and you create a new event that is recurring weekly on Fridays. Did you ever wanted such an event to occur on the day it has been created? I think if you want Fridays that’s Fridays only. Of course you could add an exception later, so the event is moved to another day for a specific occurrence, but that’s another story.
Now if you create such an event, first occurrence will be on this Thursday and Friday. I believe in most cases this is not an intended behavior. It also creates confusion if you use more than one client and they handle this case differently. You will see a difference in displaying your calendar across clients.
This is how Kolab works and for example Thunderbird Lightning too, but not Outlook. In Kolab we’ll solve this by additional checkbox and will default to Outlook behavior. If checked, the start date of the event will be aligned with the first occurrence of the event (on or after the original creation date).