Free Association (libical)

icalcomponent_foreach_recurrence returns all RDATES, but it should only
return those that are within the specified time span.

Fix is easy:
--- icalcomponent.c 2009-01-08 18:50:22.000000000 +0200
+++ icalcomponent.c.new 2009-10-18 15:41:32.000000000 +0300
@@ -1097,6 +1097,7 @@

if (!icalproperty_recurrence_is_excluded(comp, &dtstart,
&rdate_period.time)) {
/** call callback action **/
+ if (icaltime_span_overlaps(&recurspan, &limit_span))
(*callback) (comp, &recurspan, callback_data);
}
comp->property_iterator = property_iterator;

This is fixed in Orage (Xfce calendar) as explained.