Which function would be inappropriate for changing a date format?

The function that is inappropriate for changing a date format is toString(). This function is primarily used to convert data types into string representations. While it can display a date as a string, it does not provide options for modifying the format in which the date is represented. Instead, it simply converts the date to its default string representation without allowing for any customization.

In contrast, functions like todate(), change(), and date() are specifically designed for manipulating and transforming date values. The todate() function is used to convert strings to date objects, while the change() function can be used for modifying date information. The date() function allows you to create new date instances based on input parameters. These functionalities are focused on handling and formatting date data, making them much more suitable for date manipulation than toString().