diff --git a/yuthon_hr_attendance/models/yuthon_shift_planning.py b/yuthon_hr_attendance/models/yuthon_shift_planning.py
index d02234fad..a24cc292d 100644
--- a/yuthon_hr_attendance/models/yuthon_shift_planning.py
+++ b/yuthon_hr_attendance/models/yuthon_shift_planning.py
@@ -86,7 +86,7 @@ class YuthonShiftPlanning(models.Model):
                                 pass  # 跳过休息日
                             else:
                                 if current_date.day == 31:
-                                    self.create_planning_slot(record, role_a, role[role_index-1], current_date)
+                                    self.create_planning_slot(record, role_a, role[role_index-2], current_date)
                                 else:
                                     self.create_planning_slot(record, role_a, role[role_index], current_date)
                             current_date += timedelta(days=1)