On Thursday, 14 Sep 2017 at 11:05, Göktuğ Kayaalp wrote:
> It seems to me that my only option ATM is what Eric S Fraga pointed,
> but that's rather tedious as things like lessons change during the
> year (different classrooms, time changes).

Funnily enough, it is for changes in lecture halls etc. that I use the
clone subtree approach: that way each entry can have different
information.  I specify the defaults in the first entry; clone the
number I want and then modify any special cases as required
(e.g. different lecture hall, delete the reading week slot, ...).

But, of course, YMMV!

-- 
: Eric S Fraga via Emacs 26.0.50, Org release_9.1-57-gc6e563