(a) A license under this chapter is valid for a term of two or more years as determined by board rule.
(a-1) The board by rule may adopt a system under which licenses expire on various dates during the year.

(b) For a year in which the license expiration date is changed, license fees payable on January 1 shall be prorated on a monthly basis so that each license holder pays only the portion of the fee that is allocable to the number of months during which the license is valid. On renewal of the license on the new expiration date, the total license renewal fee is payable.