[O] using holiday dates from an ICAL calendar

[Julien Cubizolles]

I need to define weekly appointments, except during the school
holidays. I know org-class provides a way to exclude some weeks from
recurring events but I was wondering if some clever use of sexp would
make it possible to use the weeks/days of holiday from a public ical
calendar (like
https://www.google.com/calendar/ical/bubn5utkn054pluh4v44nu6ok62e1dbo%40import.calendar.google.com/public/basic.ics).

Did somebody ever try it ?