(a) Except as provided by this section, a school district may not begin instruction for students for a school year before the fourth Monday in August. A school district may:
(1) begin instruction for students for a school year before the fourth Monday in August if the district operates a year-round system under § 25.084; or
(2) begin instruction for students for a school year on or after the first Monday in August at a campus or at not more than 20 percent of the campuses in the district if:
(A) the district has a student enrollment of 190,000 or more;
(B) the district at the beginning of the school year provides, financed with local funds, days of instruction for students at the campus or at each of the multiple campuses, in addition to the minimum number of days of instruction required under § 25.081;
(C) the campus or each of the multiple campuses are undergoing comprehensive reform, as determined by the board of trustees of the district; and
(D) a majority of the students at the campus or at each of the multiple campuses are educationally disadvantaged.
(b) Notwithstanding Subsection (a), a school district that does not offer each grade level from kindergarten through grade 12 and whose prospective or former students generally attend school in another state for the grade levels the district does not offer may start school on any date permitted under Subsection (a) or the law of the other state.