String was not recognized as a valid DateTime " format dd/MM/yyyy"

Question

I am trying to convert my string formatted value to date type with format dd/MM/yyyy.

this.Text="22/11/2009";

DateTime date = DateTime.Parse(this.Text);

What is the problem ? It has a second override which asks for IFormatProvider. What is this? Do I need to pass this also? If Yes how to use it for this case?

Edit

What are the differences between Parse and ParseExact?

Edit 2

Both answers of Slaks and Sam are working for me, currently user is giving the input but this will be assured by me that they are valid by using maskTextbox.

Which answer is better considering all aspects like type saftey, performance or something you feel like

Answer 1

Use DateTime.ParseExact.

this.Text="22/11/2009";

DateTime date = DateTime.ParseExact(this.Text, "dd/MM/yyyy", null);