In our first stab and planning and pacing we planned for every day, all of our lessons moving through the unit, and then on to the next unit. It wasn't long before we were showing up to team meetings apologizing to each other for being behind on our pacing. Our reasons for lagging behind were varied, some needed time to reteach, another was sick and the sub couldn't keep up, a third person was inspired to try something innovative, but it took a little longer. Then there were assemblies, evacuation drills, and the whole host of other things that popped up to steal instructional time from our days.
In our next round of planning, I proposed we add flex days to our units. A flex day is simply a day we haven't planned a specific lesson for. It's a blank, and it is moveable. We put them on the Friday's of our schedule, but in practice a teacher could use them any day he or she needed to. If I had to be absent on Wednesday, I used that as our flex day for that week. If I wanted to try a new tech tool with my students ,and it didn't fit in the regular flow of our curriculum, I could do it on a flex day. If my students needed re-teaching, or just needed more time than I anticipated on a project, we had a flex day to work with.
Almost immediately, our team was happier. We felt like we had enough time to make sure our students understood the concepts. It gave us autonomy to implement adaptations to the curriculum and "pilot" new ideas. It made having a sub day much easier because we could leave a lesson our students could do independently. In my own classroom, I most often used flex days for an article of the week assignment, or to catch up on lingering work. It is never a wasted day, just a day where my students and I get to determine our own top priorities.
If you are planning with a team, and pacing out your unit plans, I highly recommend building in one day a week as a flexible day. It gives teachers the autonomy to make decisions about what their students need. It accounts for the vagaries of life and the kinds of events that happen in schools that take class time. It is a realistic approach to pacing curriculum, so that teachers and students have a chance to catch up, reflect, and try new approaches.
All Hail the Flex Day!