Sooooo I'm confused as to when your rank updates, is it actually twice a month like I read somewhere??
Not surprisingly, previous posts don't fully answer your question.
Your rank only updates when you've passed the minimum activity threshold for the next rank.
Assuming you've (A) made at least one post in each two week cycle since you joined the forum, and (B) you have more posts than the number of days you've been active on this forum. Your activity will update every other week, not just twice a month. And it usually occurs on a Tuesday or a Wednesday.
You cannot have activity higher than the number of days you've been active in the forum (with the exception of your first 14 days).