This whole concept of texting all day long is stupid. Is this now a thing to do?

To me, it's the same thing as talking for way too long on the phone. The reason why it is bad is the same as I've told you before. It has you both running out of things to say before you ever even get to have your first date! You both will get bored of each other very quickly as you will run out of things to say.

Also, the thrill of constantly hearing that little ping of a message on your phone, feeling constant attention from him, cannot possibly continue as people have lives and are busy, plus you will run out of things to say. What can you possibly say all day in texts with someone? Now I am on the toilet... now I am washing dishes... did I tell you about the time I...?

Save your pearls for when you are on the dates with him.

So, as for when you should text him back... I'd say just don't. I'm sure he will text you again since he is interested. Then put this back on track by not doing the constant text thing. Tell him you are looking forward to you date and keep the texting brief. Otherwise, you may never get to that date one week from now.