Yes. Next!
Oh, you want more details? OK...
if you try to compile that, you will get an error:
Cannot implicitly convert type 'string' to 'System.DateTime'
Because you can't just assign a string to a DateTime any more than you can push a square peg in a round hole.
DateTime is not a string data type: it's a value which represents the number of milliseconds since and arbitrary point of time. Even if you wanted to assign a "blank" value to it, you can't, because just like
integer
it doesn't have a concept of "blank number" - it has a zero, just like integers do (DateTime.MinValue) but it doesn't have a "blank" value, so even if your tried the "proper" way to assign a string value to a DateTime by using DateTime.Parse or DateTime.ParseExact it would throw an exception if you tried to parse a blank string!
Think about what you are trying to achieve and there may be a better way to try and get there - but that isn't going to work!