SB 575 makes the following changes to collective bargaining for teachers: - Removes hours as a negotiable item and instead makes hours a mandatory part of discussion. - Requires the number of hours per day a teacher is expected to work to be included in their teaching contract. - Limits what can be included in contracts depending on if they were ratified before or after specific dates in 2011. - Requires contracts to expire at the end of state budget bienniums which last two years.