I just think that once you get what that tiny yellow plus is made for 
(what is one of the things that is quite clear, that is to me it was, 
then), you will instantly understand what the minus does.

But despite that, bulk actions really seem necessary to me. Not only 
deletion is tedious, but also e.g. changing categories and setting up 
recurrence ("Repeat this events/categories until this date" - class 
schedule, again). You could also put a little checkbox to each event 
in week view and have the actions bundled at top and bottom, as it is 
done for mails already.

So, yes, you could abstract this request a little and consider bulk 
actions für events in general. You have to be very considerate of what 
actions can be bulked and how to present it, though.

I appreciate your perspective as someone advocating for a feature that 
you would find useful and use. But are you really saying that because 
our UI is somewhat confusing now, it's no big deal to add more 
confusing things to it?

Many things in Horde are confusing as it is. But it is, obviously, 
your decision.

That looks really confusing to me. I'm not saying never, but for now 
I'm marking this rejected.

This works if and only if you can search by category as well as define 
time spans more freely. Both is not possible today.

As for GUI cluttering: There already is a little '+' Link next to day 
labels for adding events. Why not add a '-' on the other side for 
deleting? (see attachment) This would solve the problem on a per-day 
basis, at least. Given deletion per day (with the choices pointed out 
earlier), I would save loads of time already with minimal GUI impact.

I agree with Chuck. As a compromise I could see that we add checkboxes 
to the search result list and allow event deletion from there, though.

There also has to be enough use for it to justify including it in the 
user interface and thus making the UI more complicated. That's what I 
doubt here.

It would still take at least one click plus a little waiting time per 
event at the least. It is a simple matter of complexity: I propose 
O(1) instead of O(n), n the number of events you have to delete. On 
the other hand, you can speed up individual deletes as much as you 
want, you will never leave O(n) if you stick to the model we currently 
have ;)

What you have to decide is wether this improves a set of use cases 
that is significant enough to justify the effort or not. In my 
opinion, it does, since I believe the function should be not too 
complicated and should not have any side effects. But, of course, I am 
not privy to your code base.

I think this is more an argument for a faster UI/experience for 
deleting individual recurrences than it is a feature that would be 
generally useful.

Use Case: I create a series of recurring events for, say, my lectures 
and excercises. Since recurrence can only be set up for simple 
intervals, christmas gets plastered by those events as well. Now I 
have to remove every single event in the two weeks around christmas. 
Two clicks each plus page load time.

Solution: Introduce a function "Clear X" for X out of {day, week, 
month}; maybe even allowing an arbitrary time range is nice and 
simple. There should be several options:
* Remove every single event in the selected time frame
* Remove events from selected categories (one checkbox each) in the 
selected time frame
* Remove exactly the selected events (long list with checkbox for each event)