2 files changed, 13 insertions, 1 deletions

diff --git a/lib/chaos_calendar/ical_occurrences.c b/lib/chaos_calendar/ical_occurrences.c
index 6515451..e59c1ed 100644
--- a/lib/chaos_calendar/ical_occurrences.c
+++ b/lib/chaos_calendar/ical_occurrences.c
@@ -62,3 +62,15 @@ VALUE occurrences( VALUE dtstart, VALUE dtend, char *rrule ) {
   icalrecur_iterator_free(ritr);
   return occurr;
 }
+
+VALUE duration_to_fixnum( char * duration ) {
+  icalerror_clear_errno();
+  icalerror_set_error_state( ICAL_MALFORMEDDATA_ERROR, ICAL_ERROR_NONFATAL);
+
+  struct icaldurationtype dur_struct = icaldurationtype_from_string( duration );
+
+  if( icaldurationtype_is_bad_duration( dur_struct ) )
+    rb_raise(rb_eArgError, "Malformed Duration");
+
+  return LONG2FIX(icaldurationtype_as_int( dur_struct ));
+}
diff --git a/lib/chaos_calendar/ical_occurrences.i b/lib/chaos_calendar/ical_occurrences.i
index 3f87628..1e91701 100644
--- a/lib/chaos_calendar/ical_occurrences.i
+++ b/lib/chaos_calendar/ical_occurrences.i
@@ -2,5 +2,5 @@
 
 %inline {
   VALUE occurrences( VALUE dtstart, VALUE dtend, char * rrule );
+  VALUE duration_to_fixnum( char * duration );
 }
-