I received a very nice email from a parent this weekend asking about the open house on Friday. In her email she asked if the open house could start later in the afternoon, so that it would be possible for working parents to attend. I have never explained the rationale for the timing of the open house so I am posting the bulk of my response to her (with names removed) 
Thank you for the note and the suggestion. You are absolutely right, the timing of the open house on Friday afternoon is not convenient for working parents. Unfortunately, I don’t see a better alternative. Contractually, the teacher work day ends at 4:05. We have many, many teachers who consistently work past that time, but I don’t feel comfortable scheduling an event that I want all the teachers to be at that ends past 4:00. In addition, even though we advertise the event for 45 minutes, it really lasts more like an hour and since it takes place the last day before school starts, I need to have a quick faculty meeting right before the teachers leave that day to make sure we are all ready for the first day of school and any issues came up at the open house can be addressed. So working backward, 2:30 is really the latest we can start it.
The open house is a very informal afternoon which many families do not attend and it is much less important than our Back to School nights and conferences for which we always have evening hours. This year we made one additional change. We moved our kindergarten orientation from Friday afternoon to Thursday evening so that it was easier for working parents to attend.
