First off, congrats on getting the two numbers of girls that you see as very attractive!
As far as when to call, I've said before and will say again. Act faster, don't wait, call the next day. Waiting to not seem desperate is an AFC move. I'de rather seed a call when I get a number by playfully saying, "I'm going to call you tomorrow, wait by the phone."
I'll also send her a text right then and there while I am still with her saying, "OMG is that NSM that your talking too? That guy is awesome!"
I use the first phone call to set up the day 2. I don't go right into setting up the day two, instead small talk first, seed the day two, more small talk, book day two, small talk, and done. Keep it brief on the phone. Texting and calling at first should only be to keep things moving forwards. When you get your day two, you can have personal time with her, ramp up kino, kiss close mid way through, and establish what you and her relationship will be like.