I actually support the way that the school districts in Colorado and Idaho did this reform.
They took a day away from formal instruction on Fridays. 2 Fridays a month are professional development, 1 day is special tutoring for students that need the extra help, and the final friday is left for the teachers own discretion. Administrators, school board officials, and politicians believe that teachers should only need 1 class period to plan their day. A lot of teachers don’t even have that luxury. They continue their work after school and on the weekends but do not get extra pay for working more. Since teachers are not paid hourly and paid on salary and in most states based on performance, they do not get overtime pay.
I’ve known teachers who stay at their school preparing lessons and activities till 6, 7, or even 8pm. But having these set-aside days to have professional development, lesson planning time, and personal time to do what they need to as teachers I think will pay off in the end. As of right now in Colorado in their first year their reading scores increased by a few margins. Math scores stayed stagnant.