Without wishing to come across as an a**hole here...aren't long hours sort of inherent to teaching? Obviously there are going to be ways we as society can make teaching a more enjoyable profession, but how do you go about shortening the work day when you've got the school day followed by marking and lesson planning on top?
By giving time DURING the school day to get the job done, and minimizing red tape. One major problem is that the larger and more heterogenous classes get, the more grading and planning work piles up, and the harder it is to help individuals during class with one-on-one attention. So the teacher ends up using their grading, planning, and lunch time to meet with those students later, and takes all that paperwork home. Administration piles even more kids into the class, saying, "You're not overworked: it was your CHOICE to teach through your break," because they know full well that anyone who chose this profession is going to have a hard time drawing that line when they know there are struggling kids who need the help.
One simple way is to schedule enough teachers so they have time for documentation, planning, follow-ups and grading during school hours.
That might mean every teacher gets only 2 teaching hours/day to have time to do the rest, could also mean they get support with documentation, follow-ups and similar, through other functions.