diff --git a/yuthon_hr_attendance/models/yuthon_shift_planning.py b/yuthon_hr_attendance/models/yuthon_shift_planning.py
index a4ddb2af5..3e51a8c31 100644
--- a/yuthon_hr_attendance/models/yuthon_shift_planning.py
+++ b/yuthon_hr_attendance/models/yuthon_shift_planning.py
@@ -28,7 +28,7 @@ class YuthonShiftPlanning(models.Model):
         target_year = year if (not next_date or selected_month != 12) else year + 1
         start_date = datetime(target_year, target_month, 1)
         next_month_first_day = start_date + relativedelta(months=1)
-        end_date = next_month_first_day - relativedelta(seconds=1)
+        end_date = next_month_first_day  - timedelta(days=1)
 
         existing_slots = self.env['planning.slot'].search([
             ('role_id.name', '=', '保安部'),