I would think it a little psycho if some guy I just met called me several times the next day. Other than that.... I'm a bit weird when it comes to timeliness. I have broken up with guys because they were chronically tardy. So if you are going to call "tomorrow," call TOMORROW!
Why not just say, "I'll call you this week" or "I'll call you in a few days?" Much simpler and then you don't have to worry about deadlines.
Allie
