Umm... I think I am a bit non-traditional in my approach to things. I don't pay attention much to gender roles, etc... Actually, I find most of that trying to apply those kinds of things in my life becomes quite tedious...
When is it okay to start calling a man? Um... Whenever you would like I would say.
There are different factors that are involved in deciding to call someone.
For example, if you met a man today while out and you exchanged numbers after a short conversation (and not because of time constraints), calling him that night might not make much sense. The conversation being short may be an indication that although there was a connection, it was not a very strong one.
BUT what if you met a man today and you had a two hour conversation and had to be virtually dragged away from each other? Calling him to wish him a good night (not to have a drawn out long conversation) seems quite reasonable.
NOW here something that is very very very very (did I mention very?) imporant: Calling someone once is okay. Calling/Texting someone on repeat is NOT okay (especially at odd hours). This is often the problem I think for women.
For some strange reason, many of believe that men have forgotten how to respond to that "Missed Call" message or the sound of their phone ringing... or beeping because of the new voicemail. Well, they haven't. If a man has not answered you, it is not because he suddenly lost his hands or his voice, or developed amnesia... It is his choice not to answer.
So... Taking all of that into consideration: Again, when is it okay to start calling a man?
Whenever you feel like it in my opinion. As long as you can treat him and yourself with respect.
I hope this helps!
In every moment... a choice...