--- date/date_api_sql.inc	2008-08-26 19:47:45.000000000 +0200
+++ date/date_api_sql_new.inc	2008-08-27 12:44:46.000000000 +0200
@@ -190,7 +190,7 @@ class date_sql_handler {
         case 'mysqli':
           return "ADDTIME($field, SEC_TO_TIME($offset))";
         case 'pgsql':
-          return "($field + 'INTERVAL $offset SECONDS')";;
+          return "($field + INTERVAL '$offset SECONDS')";;
       }
     }
     return $field;
@@ -772,4 +772,4 @@ class date_sql_handler {
       return array($min_date, $max_date);
     }
   }
-}
\ No newline at end of file
+}