Comment 24 for bug 258613

I can confirm this issue on KDE 4.4.3 / OpenSuSE 11.2.
What I see:

- Creating an event for Tuesday 2010-05-11, recurring weekly (4 times)
- Move the event to Wednesday 2010-05-12
-> The event disappears from the current week, and the first occurrence will be next week Tuesday (2010-05-18)

It's the same behaviour both moving by mouse or changing the event's start date from the event property dialog.

My interpretation:
Weekly recurrence of an event is based on selecting the day of the week on which the event should occur.
Upon creation of the event, this information is pre-defaulted to the day of the event start date.
Changing the event start date later on only changes the time range for the whole event (like: when is the first event allowed to occur), but not the day of the week when it will occur.

I could imagine that we have similar effects on monthly or yearly recurring events, although the problem might not hit so often in those cases.
However, looking at the possible choices in those cases (like "every 11th day of the month" vs "every second Tuesday of the month"), I guess there is no easy solution to apply "event dragged by mouse" changes easily to those repetition rules.

I even would say, the behavior is consistent with the design -- albeit not very intuitive for the user.

What might help:
1. An additional choice (which should be the default IMHO) for weekly recurrence; something like "on the same day of week like the start date of the series" (sorry, I couldn't find a more catchy phrase).

2. An information to the user in cases where the recurrence rules could not be updated automatically (not that trivial to find out when this would be, probably).