Throwing a Date in IDE via Editing a value?

Sorry. I thought I was being clear by the word edit. When you debug, you can see the value, but you also have the opportunity to edit the value before it is used.
I thought by changing the value before it is used would result in an error.
I edited the value for a string before it was converted to a date, but it didn’t throw an error.
To prove it would throw I went and edited the text to be read in and it threw an error.