[O] 'org-calendar-holiday's not in an org agenda org file

[Enda]

In order to include holidays in the org agenda for current day or week (M-x 
org-agenda RET a), you have to put the following line in one of the 
org-agenda-files:

%%(org-calendar-holiday)

Is there a way to include holidays in the org agenda for current day or week 
without putting "%%(org-calendar-holiday)" in one of the org agenda org files?


-- Enda