-DATE-LIST is a list of diary entries. Return only those matching DATE."
- (mapconcat (lambda (x) (cal-html-htmlify-entry x))
+DATE-LIST is a list of diary entries. Return only those matching DATE.
+Optional argument HOLIDAYS non-nil means the input is actually a list
+of holidays, rather than diary entries."
+ (mapconcat (lambda (x) (cal-html-htmlify-entry x (if holidays "HOLIDAY")))