We are about 11 weeks in to the school year and there is a definite pattern developing. I noticed this with my older son when he was in high school and now that my youngest has just started his Freshman year, here it is again! They seem to be the grumpiest on Thursdays! I think it is because the fatigue from the week is setting in.  Lot's of whining and talking back. I get it, I am tired sometimes too!