(a) Except as provided by Subsection (b) or (c), a stamp issued under this subchapter is valid for fishing only during the yearly period for which the stamp is issued without regard to the date on which the stamp 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 stamp fee for a stamp issued during a transition period at an amount lower than prescribed in this subchapter and provide for a stamp term for a transition period that is shorter or longer than a year.
(b) A saltwater sportfishing stamp issued before September 1 or another date set by the commission that does not expire until August 31 of the following year or another date set by the commission is valid from the date of issuance through August 31 of the following year or another date set by the commission.

(c) A saltwater sportfishing stamp issued in conjunction with a license issued under § 46.005 or 46.0051 of this code expires at the same time the license expires or on the expiration date printed on the stamp, whichever is later.