Tex. Parks & Wild. Code § 65.0071

A license issued under this chapter is valid only during the yearly period for which the license is issued without regard to the date on which the license is acquired. Each yearly period begins on September 1 or another date set by the commission and extends through August 31 of the next year or another date set by the commission. The commission by rule may set the amount of a license fee for a license issued during a transition period at an amount lower than prescribed in this chapter and provide for a license term for a transition period that is shorter or longer than a year.