More working off the long mishnah - beginning with discussion of the watches of the kohanim, and when they would need to cut their hair and launder their clothes - to make sure they're presentable while on the watch. Among other populations, and how frequently they cut their hair to make sure they don't get scruffy in appearance. Based on nazir. Also, days when eulogizing is not permitted, as connected to the daily offering (even in its absence), and the dynamic with the Sadducees. The month of Nisan follows suit, because of the dynamic with the Baitusim. There's joy in the success of the rabbis over these sects.