diff --git a/date_repeat/date_repeat_calc.inc b/date_repeat/date_repeat_calc.inc
index 2a02d94..d6ceb3f 100644
--- a/date_repeat/date_repeat_calc.inc
+++ b/date_repeat/date_repeat_calc.inc
@@ -238,6 +238,9 @@ function _date_repeat_calc($rrule, $start, $end, $exceptions, $timezone, $additi
       }
     }
     ksort($week_days);
+    // This is needed if weekly interval > 1. Otherwise if start date is the
+    // first of the days selected, the weeks are not selected correctly.
+    $day = reset($rrule['BYDAY']);
 
     // BYDAYs with parameters like -1SU (last Sun) or 2TH (second Thur)
     // need to be processed one month or year at a time.
@@ -578,4 +581,4 @@ function date_repeat_set_year_day($date_in, $day, $count = 1, $direction = '+',
     }
   }
   return $date_in;
-}
\ No newline at end of file
+}