diff --git a/dba/rrule_functions.sql b/dba/rrule_functions.sql
index e64ff540..d36cd778 100644
--- a/dba/rrule_functions.sql
+++ b/dba/rrule_functions.sql
@@ -184,3 +184,8 @@ END;
 ' LANGUAGE 'plpgsql' IMMUTABLE STRICT;
 
 
+CREATE or REPLACE FUNCTION event_has_exceptions( TEXT ) RETURNS BOOLEAN AS '
+  SELECT $1 ~ ''\nRECURRENCE-ID(;TZID=[^:]+)?:[[:space:]]*[[:digit:]]{8}(T[[:digit:]]{6})?''
+' LANGUAGE 'sql' IMMUTABLE STRICT;
+
+