(a) Except as authorized under Subsection (b) of this section, § 25.0815, § 25.084, or § 29.0821, for each school year each school district must operate for at least 75,600 minutes, including time allocated for instruction, intermissions, and recesses for students.
(b) The commissioner may approve the operation of schools for fewer than the number of minutes required under Subsection (a) if disaster, flood, extreme weather conditions, fuel curtailment, or another calamity causes the closing of schools.

(c) If the commissioner does not approve reduced operation time under Subsection (b), a school district may add additional minutes to the end of the district’s normal school hours as necessary to compensate for minutes lost due to school closures caused by disaster, flood, extreme weather conditions, fuel curtailment, or another calamity.
(d) The commissioner may adopt rules to implement this section, including rules:
(1) for the application, on the basis of the minimum minutes of operation required by Subsection (a), of any provision of this title that refers to a minimum number of days of instruction under this section;
(2) to determine the minutes of operation that are equivalent to a day;
(3) defining minutes of operation and instructional time; and
(4) establishing the minimum number of minutes of instructional time required for a full-day and a half-day program to meet the time requirements under Subsection (a).
(e) A school district or education program is exempt from the minimum minutes of operation requirement if the district’s or program’s average daily attendance is calculated under § 48.005(j).
(f) The commissioner may proportionally reduce the amount of funding a district receives under Chapter 46, 48, or 49 and the average daily attendance calculation for the district if the district operates on a calendar that provides fewer minutes of operation than required under Subsection (a).
(g) A school district may not provide student instruction on Memorial Day. If a school district would be required to provide student instruction on Memorial Day to compensate for minutes of instruction lost because of school closures caused by disaster, flood, extreme weather conditions, fuel curtailment, or another calamity, the commissioner shall approve the instruction of students for fewer than the number of minutes required under Subsection (a).