Again, it seems like most of these posts may be either overanalyzing the situation, or else they are throwing out little DJ "catch phrases" to justify why a person should or should not do something.
Before the days of the DJ message board, I'm hoping some guys here have gone out and actually interacted face to face with people, and I'm sure you have. To me, those are the days of innocence, before your mind got cluttered with all these rules. "Can't ask her out on a Saturday", "Can't call her for 3 days after you've seen her in black clothes", "Can't talk on the phone for more than 5 minutes" (actually, that one is probably ok), "Can't have coffee on the first date", "Can't have coffee with a danish on the first date"...and the list goes on.
My point is that when you're with a girl and things are going great, nobody is thinking about this crap. I know I'm not. I've probably broken rules left and right just by being so oblivious to the rules, but you have to realize that almost nobody knows about these rules except for folks that spend too much time analyzing stuff and not taking action.
So call her the next day, for crying out loud. What the heck is going to happen that's so earth-shattering? Just make it sincere, that's all. Don't call because someone told you to, call because you want to. That to me is all about being who you want to be and doing what you feel is right. There's some common sense beyond all these rules here guys. Don't overlook it.