Clearly schools need time with all teachers and staff together to talk about systems, safety and other broad topics. Let's do that right before school starts, we're all together then.
After that's over, and throughout the year, what I want as a teacher is content specific time to work with my colleagues. We have common planning time at my school Thursdays after school, but once a month I've got a department chair meeting and every week one or more of our team is coaching a sport or running the after-school tutoring session in the library. The system is set up so that we have a hard time getting together regularly and being effective.
As teachers we rarely get the time we could use to work together on things.