Sorry, I made a quick search but found nothing about this.
Either I got it completely wrong or the example of function building on P 163 is completely broken. The PC try to build 3 function for a total of 38 days (one month + one week + one day). They take four times the required amount of time which makes 38 x 4 = 152...oh no wait, 44 days in order to get a +4 modifier. Well, they obviously cheat because P. 53 states that four times the amount of required time is a +2 modifier and it is the maximum modifier one can get. Did I miss something or is the example actually broken ?