When I was there, whenever a new platoon showed up we always made fun of the guys who had long hair still. By the time they got to he barbers they couldn't wait to get it shaved off.
Same thing happened when I went thru; in 1989. The more things change...the more they stay the same.
IIRC, we got our haircuts around Thursday of week 1, the same day we got issued our kit. Until that, we were the stupidiot platoon, stomping around with 120 different versions of various drill movements, some guys with long hair, all of us in our "civies" to the amusement of the other 9 platooons of "Senior" recruits in Cornwallis at the time.
Then, come Sunday of Week 2, we'd no longer be the Goon Platoon, we were BETTER than those dumba$$es, because we had our workdress and shaved heads and we had more TI than they did.

Yup, Week 2 and we thought we were the shyte now!!

Snaking thru the line at Champlain Hall, we could roughly guess what week a recruit was in by how much hair had grown back on the top.