(a) Except as provided by Subsection (b), a license to practice pharmacy expires December 31 of each year or of every other year, as determined by the board.
(b) The board may adopt a system under which licenses to practice pharmacy expire on various dates during the year.

(c) If the board changes the expiration date of a license, the board shall prorate the license renewal fee to cover the months for which the license is valid for the year in which the date is changed. The total license renewal fee is due on the new expiration date.