89.1075. General Program Requirements and Local District Procedures. [Excerpt] (d) Students with disabilities shall have available an instructional day commensurate with that of students without disabilities. The ARD committee shall determine the appropriate instructional setting and length of day for each student, and these shall be specified in the student's IEP.

Temporary absence resulting from an appointment with a health-care professional for the student or the student’s child if the student commences classes or returns to school on the same day of the appointment. The appointment must be supported by a document such as a note from the health-care professional. “Temporary absence” includes the temporary absence of a student diagnosed with autism spectrum disorder on the day of the student’s appointment with a health-care practitioner to receive a generally recognized service for persons with autism spectrum disorder, including applied behavioral analysis, speech therapy, and occupational therapy.

Education Code 25.087(b)(2), (b-3); 19 TAC 129.21(j)(3) [See FEB]

Students with disabilities must receive a commensurate school day. This means students with disabilities and their non-disabled peers:
(a) have a school day with same beginning and end time, and
(b) attend school for the same number of hours.

The school day for students with disabilities cannot be shortened due to administrative convenience such as the schedule of bus routes, or parents’ convenience such as their work location or schedule.

An Admission, Review, and Dismissal/Individualized Education Program (ARD/IEP) committee may consider, review, and document a shorter school day based on the individual needs of the student and based on evidence of court documentation ordering a shortened day, or ARD/IEP documentation verifying a medically-relevant justification for a shortened school day.

This requirement applies to all students with disabilities ages 3-21 regardless of their disability, type of class, or program.