There was a move in some districts fifteen or so years ago to reduce or eliminate extra days and increase the stipends for band directors, coaches, etc. The reason behind it was that when the ISD gave a pay raise, those positions got a bigger raise than other teachers because the raise was an increase to the daily rate.

Apparently caused resentment in some places, and heard of one place where the admin came out and said that they had x dollars for a salary increase, so the overall amount of the raise was less due to the number of extended day contracts carving out a bigger piece of that dollar amount.