This section applies to all employees in the State Personnel Management System. An employee subject to this section is entitled to extra pay, known as shift differential pay, if the employee: is employed in a position designated for this purpose; and works on a shift that starts on or after 2:00 p.m. and on or before 1:00 a.m. A State-employed fire fighter is entitled to shift differential pay for qualifying hours if the fire fighter works on a shift of at least 8 hours, regardless of the time that the shift starts. The Secretary shall adopt regulations for the payment of shift differential pay. The regulations adopted under this section shall provide for fairness and equity among all employees in consideration of: the hours worked; conditions and places of employment; prevailing practices in the locality; and other factors that the Secretary considers relevant under the circumstances.