If you want the user to input a date in a Userform, you could of course just use a Textbox. But you'd have to write a lot of code to check whether the user put in a correct date, in the correct format, within the allowed timeframe, etc. Using calendar controls is the easier way, it looks nicer and you don't have to do all these checks by yourself.

( How to use the DateTimePicker and MonthView controls... )