Most Helpful Guy
1. Pick-up to first date: under 48h
After I just picked her up on the street, around 48h. So I will call her the day after tomorrow. Dependind on what we've talked on the street, I might call her sooner. Putting time between you two does nothing to help your "thing", but quite opposite: makes her think you are an insecure shy guy or either she's one of your other 14 dates this week.
2. After the first date: any decent time of any day
I impose no other restraints on calling other that the call has to be placed at a decent hour of the day. Calls at 03:30AM are highly uncalled for.
2'. After the first sexual encounter: the next morning
Supposing you had a great night and you sleep separately pe having just split in the morning, I like to call her around 09:00-10:00 in the morning to tell her I enjoyed last evening/night. That builds up her confidence. The thing is that if you tell her while you're having sex or sometimes even right after, you somehow throw yourself ar her. One should be retarded to NOT feel on the spot if one's partner is actually having a good (fucking) time or not.
3. From n'th date to n'th+1 date: again anytime, as long as it's still a decent time.
For example: I called my then 1 year girlfriend at 07:00AM on her birthday to say "Happy Birthday!" and come downstairs and get her present (a pet baby husky). To this day she rubs it in my face that I woke her up too early.
Bottom line, I don't want to overwhelm her with phone calls, although I would highly appreciate if she would tell me I can call her anytime of the day (and night). Personally, I have no problem picking up the phone at night, because after the conversation, I easily fall asleep again. And I would like to meet a significant other that behaves the same, because emergencies occur in the middle of the night, too. And not "being able" to call her at that specific time is something that I hate. It happened to me to be in a different country and in need of buying a last minute plane ticket but my credit card was rejected. So... I'd highly appreciate if my SO would have problems sleeping that night because she woke up to help me.