Hi DenimGirl.
You bring up a good point about what the issue is. I guess it is a very special event and it shows you recognize it is not an ordinary thing. I would say by the second or so date, one can begin to show their preferred style of dress.
I am not a suit guy. I prefer denim, a nice shirt, leather jacket (not anymore), a bandana reppin’ my gang affiliation (not anymore) ..lol. But when my Rabbi said there is someone he wants me to meet, he kinda nudged me and said I should wear a suit and a hat. The irony is the lady I was meeting told me she told him I dont have to dress up. lol Ultimately, who knows? Take in the advice and come to your own consensus, and have a fantastic time on the date. It is exciting!!