In a self-contained classroom, I have a great deal of say over when we learn what. And I cannot allow a set schedule to get in the way. Just because the hour has ended, and the schedule dictates a change in subject, does not mean you have to stop. How many times have you dug into a lesson - really gotten your students engaged in something - and stopped because the clock screamed at you?
Stop it.
Take that "teachable moment" and run with it.
I've been known to stick with a lesson for hours, even for an entire day, because I'm smart enough to know what's working for my students.
Yes, I hear you. An administrator can be so controlling and heavy-handed that s/he will not permit you the professional respect you need to make decisions for your class. Some would have you teach the same thing at the same time as your grade level peers. They want to see you on the same page and teaching in the same manner.
I don't wish to sound aggressive, but I will fight that concept. Who knows my classroom, might students, and my style better than I do? If it is a teacher's contractual duty to teach students, then any administrator worth his/her salt will respectfully allow the teachers in the building to teach.
That includes this preposterous idea that a teacher should understand best what to do in the classroom. My friends, we are the tip of the spear. We are the ones on the front lines in the war against ignorance.
Are any more military metaphors needed here, or are we getting the idea?
In contrast, I need the ability to shut down a lesson that isn't working. We've all had lessons that have fallen flat. Did we keep marching forward in failure? Or did we have the common sense to wave the white flag of surrender? We must know when to retreat from failure. Oh, we can still learn from the failed lesson, change it on the fly, and keep trying, or we could change the lesson altogether and try again tomorrow - but we have to be able to make changes in our schedules as the days progress.
Don't tie yourself to the schedule. Stop stopping when the bell tolls. Exercise that famous flexibility we always hear about in our field. Make this thing work for your students!
And you administrators, remember the greatest tool you have in your belt is to empower your teachers. They should know better than you what they're students need. Be their resource for support and advice, but grant them the professionalism they so desire.