it varies significantly from one to another. personally, it is depending upon the individuals who i am going to meet and how the condition of the situation for which we are going about meeting each other. if it were just a meet for lunch, it could be the same day. if it were for other purposes, it could be months and even years because the time, place, arrangement and/or situation just had to be perfect. there was no room for any error. errors are as you have to be at your best (lookwise) cuz you have one shot at this, is there any implication and complication born from this, etc...