(a) The Legislature finds that:
(1) The Consolidated Public Retirement Board has determined that retired substitute teachers should not perform substitute teaching without limit;
(2) The Consolidated Public Retirement Board has established, by rule, a maximum number of days in which a retired teacher may accept employment prior to having his or her retirement benefit reduced; and
(3) There have been inconsistencies in the manner in which county boards calculate the maximum number of days established by rule.
(b) The Consolidated Public Retirement Board may not set forth in rule a maximum number of days in which a retired teacher may accept employment prior to having his or her retirement benefit reduced that is less than one hundred forty days.
(c) For the purpose of calculating whether a retired substitute teacher has exceeded the maximum number of days in which a substitute teacher may accept employment without incurring a reduction in his or her retirement benefit, the number of days worked shall be determined by:
(1) Totaling the number of hours worked; and
(2) Dividing by the standard number of hours that a full-time teacher works per day.