I was waiting for them to say something like "then we take the random variable and multiply it by 3 to correct for this" and then explain some other, more subtle, bug. Looks like we all make stupid mistakes like this sometimes. I made a bug where I tried to get the month number for the next month, so you had to wrap at 12, but I just did "(current_month + 1) % 12" and left it at that, thinking for some reason that modulo works differently than it does in reality. Some stuff broke recently, due to that, and it was quite embarrassing.