I'm going to add my 2 cents in if you don't mind.

If a guy said to me "Lets go out to dinner Sat @6pm". I would not like this and may be the cause of me saying no.

General offer of lets go to dinner sometime is much more appealing, it gives me more freedom and less constrain thus I feel like I'm not being forced into something. I'm a very rebellious person by nature so I don't want to be told what to do, I'd feel like I'm being told what to do. However, some women may feel differently. It doesn't matter if you give an out later, you still caused those initial feelings of being trapped.

And if I say yes and don't offer a date, by no means does this mean I'm not actually interested, it means I'm genuinely so busy I'm not sure yet and/or I just didn't think about offering a date yet because I was just so excited you asked in the first place!

This may work on some women, but not all. All women are different and have their own preferences, this is a nice guideline but not perfect.