Tex. Family Code § 153.317

(a) If elected by a conservator, the court shall alter the standard possession order under Sections 153.312, 153.314, and 153.315 to provide for one or more of the following alternative beginning and ending possession times for the described periods of possession, unless the court finds that the election is not in the best interest of the child:

(1) for weekend periods of possession under Section 153.312(a)(1) during the regular school term:

(A) beginning at the time the child's school is regularly dismissed;

(B) ending at the time the child's school resumes after the weekend; or

(C) beginning at the time described by Paragraph (A) and ending at the time described by Paragraph (B);

(2) for Thursday periods of possession under Section 153.312(a)(2):

(A) beginning at the time the child's school is regularly dismissed;

(B) ending at the time the child's school resumes on Friday; or

(C) beginning at the time described by Paragraph (A) and ending at the time described by Paragraph (B);

(3) for spring vacation periods of possession under Section 153.312(b)(1), beginning at the time the child's school is dismissed for those vacations;

(4) for Christmas school vacation periods of possession under Section 153.314(1), beginning at the time the child's school is dismissed for the vacation;

(5) for Thanksgiving holiday periods of possession under Section 153.314(3), beginning at the time the child's school is dismissed for the holiday;

(6) for Father's Day periods of possession under Section 153.314(5), ending at 8 a.m. on the Monday after Father's Day weekend;

(7) for Mother's Day periods of possession under Section 153.314(6):

(A) beginning at the time the child's school is regularly dismissed on the Friday preceding Mother's Day;

(B) ending at the time the child's school resumes after Mother's Day; or

(C) beginning at the time described by Paragraph (A) and ending at the time described by Paragraph (B);

(8) for weekend periods of possession that are extended under Section 153.315(b) by a student holiday or teacher in-service day that falls on a Friday, beginning at the time the child's school is regularly dismissed on Thursday; or

(9) for weekend periods of possession that are extended under Section 153.315(a) by a student holiday or teacher in-service day that falls on a Monday, ending at 8 a.m. Tuesday.

(b) A conservator must make an election under Subsection (a) before or at the time of the rendition of a possession order. The election may be made:

(1) in a written document filed with the court; or

(2) through an oral statement made in open court on the record.