fixed README errors

README.md

@@ -54,9 +54,14 @@ Calendar = Calendar(root)
 Calendar = Calendar(root, command=user_command, ...)
 ```
 
-##### To retrieve a selected date on the calendar, use the get_date command:
+##### To retrieve a selected date on the calendar, use the getdate() command:
 ```python
-Calender.get_date()
+Calendar.getdate()
+```
+
+##### To retrieve the current date as specified by the operating system, use the getdate_today() command:
+```python
+Calendar.getdate_today()
 ```
 
 ##### To create a checkbox on the calendar, the command is as follows: