During my high school days I recall a young lady who was sent home to change - because she was wearing slacks. That year was 1967. But it was a private school.
And don't worry, the kids will begin wearing the PJs to mass - if they haven't already.
Geez.
In 1967,in my California high school, (hint, a movie was recently made about a coach there) females were only allowed to wear pants on Sadie Hawkins Day.
We used to get sent home if our shorts/skirts were less than a $1.00 bill length higher than our knees. Teachers actually stood in the halls with dollars, measuring. Unreal how things have changed.
At the private Catholic Girls' school in the next town over, they've been wearing sweats and p.j.s to school for years! I guess the more you pay, the crappier the dress? At our son's Catholic Boys' school, they're still required to come to school looking like they mean business; sport coat, ties, khakis, belt, and NO sneakers.
During my high school days, I was sent home numerous times for wearing my skirts (yes, I said skirts) too short...too short being more than an inch above the knee.