(1) No head of a department or employee therein employed at a fixed compensation shall be paid for any extra services, unless expressly authorized by law; Provided, that when any employee is required to work more than forty hours in any week he or she may, in the discretion of the department head, be granted compensatory time off at the rate of one and one-half times the hours worked in excess of forty in subsequent weeks when his or her duties will permit, or be paid a sum equivalent to one and one-half times his or her hourly pay or his or her monthly pay prorated on an hourly basis for such overtime hours.

(2) No state agency, engaged in the operation of a hospital or an establishment which is an institution primarily engaged in the care of the sick, the aged, or the mentally ill or defective who reside on the premises, shall be deemed to have violated sections 81-117 to 81-117.02 if a period of eight hours per day or eighty hours per fourteen consecutive calendar days is established for purposes of determining overtime compensation. Regular employees working on the hourly basis shall be paid wages equivalent to their regular wages for the usual number of work hours for days declared by statutory act or proclamation of the President of the United States or the Governor to be holidays; Provided, employees who have had at least one year of continuous employment with the state as hourly employees shall be guaranteed forty hours work each week.

(3) No state agency shall be deemed to have violated sections 81-117 to 81-117.02 with respect to employment in fire protection activities, law enforcement activities, including security personnel at correctional institutions, or agricultural activities, if (a) in a work period of twenty-eight consecutive days the employee receives, for four tours of duty which in the aggregate exceed two hundred hours, or (b) in the case of such employees to whom a work period of at least seven but less than twenty-eight days applies, in such work periods the employee receives, for four tours of duty which in the aggregate exceed the number of hours which bear the same ratio to the number of consecutive days of work period as two hundred hours bears to twenty-eight days, compensation at a rate not less than one and one-half times the regular rate at which the employee is paid for all hours in excess of subdivisions (a) and (b) of this subsection.