It's difficult and disruptive for students to be on a 5-day pattern of education with a homeroom teacher on a 4-day pattern. This basically necessitates schedul

It's difficult and disruptive for students to be on a 5-day pattern of education with a homeroom teacher on a 4-day pattern. This basically necessitates scheduling entirely non-core subjects on the fifth day, potentially even resulting in multiple sessions of gym in a single day. It's also not clear to me you can viably do this without increasing costs unless the school is free to choose which of the four days the teacher's work instead of the teacher doing so. For example, if the standard 4-day work week is Monday-Thursday then there is ridiculous demand for non-core subject teachers on Friday and those non-core subject teachers may even be working Monday-Thursday themselves resulting in reduced supply.