Yeah, I don't see how there could be a time frame set for something like this.

As soon as you know you can accept the consequences.

My friend, In a way you start from the get go. If you notify a lady that you are interested, you've already brought feelings in to it. Maybe not crazy passionate, throw yourself on the line kind of feelings but they are there nevertheless. I believe it starts right away with a graduated sort of system. Simple stuff, like don't ask her to marry you on date #2!! haha. If a female is interested, usually the male will know it. It's males that either repress all of their emotion, or the blurt it all out in a single sitting lol. I guess males are fairly obtuse when it comes to that. Boys will be boys I guess. My advice is baby steps. When she gives a little...you give a little...or the other way around.