Tex. Utilities Code § 141.0031: DAYS IN BILLING MONTH.

(a) A customer's bill may not include charges for a period of more than:

(1) 32 days for a billing month in which the majority of days in the billing month occur in December, January, or February; or

(2) 31 days for a billing month in which the majority of days in the billing month occur in any other month.

(b) If an extreme condition occurs or continues on or after the 29th day of a billing month described by Subsection (a)(1), the billing month may be extended by the number of days the extreme condition occurs. Extreme conditions include:

(1) iced, flooded, closed, or otherwise impassable roads in the county in which the customer resides;

(2) a natural disaster, including an earthquake, a hurricane, a tornado, or winds of more than 60 miles per hour; and

(3) civil disruption, including war, riot, or labor disruption or stoppage.

Added by Acts 2015, 84th Leg., R.S., Ch. 783 (H.B. 2558), Sec. 1, eff. September 1, 2015.