HB 604 proposes changes to the start of the school year for Texas public schools by amending Section 25.0811 of the Education Code. The bill moves the earliest allowable start date from the fourth Monday in August to the first Monday in September, aligning the schedule more closely with traditional post-Labor Day starts. Districts with year-round calendars or campuses undergoing significant reform with predominantly economically disadvantaged students may still qualify for exceptions. Importantly, the bill also restricts districts of innovation from waiving this rule under local plans, ensuring more consistent statewide implementation. These adjustments aim to balance local control with family flexibility during the summer months while maintaining fairness across districts.