[Orgmode] Extended-period events in agenda views

[Konrad Hinsen]

Hello all,

I have been a happy org-mode user for a while, using more and more of  
org-mode for more and more things. By now I have completely replaced  
my use of iCal (on the Mac) by the org-mode agenda, with no regrets.  
However, there is one feature that I am still trying to get into my  
agenda view, but I didn't find a way to do it yet.

There are a couple of long-lasting "events" that I would like to show  
in my agenda view. A typical example would be school vacation periods,  
but there are others: absences of a colleague, availability of some  
instrument, etc, Their common feature is that they can last very long  
(several weeks) and that they don't really occupy my agenda. I just  
want to know when planning something if a given day is in period X or  
not. So I'd like to see at a glance (using a specific font, color, one- 
letter prefix etc.) if a day falls into a certain predefined period.  
Simply adding a corresponding event to my agenda leads to visual  
clutter: it gets marked on every single day of the period.

Is there any way to get what I am looking for?

Thanks in advance,
  Konrad.