Update calendar_app.py

calendar_app.py

@@ -31,7 +31,7 @@ class Calendar:
         self.save_calendar()
         print(f"Reminder added for {date}: {reminder}")
 
-    def add_daterange(date_start, date_end, reminder):
+    def add_daterange(self, date_start, date_end, reminder):
         """Add a reminder for a date range."""
         for date in range(date_start, date_end+1):
             if date not in self.reminders: