Overtime for non-exempt classifications will be compensated for by pay or compensatory time at a rate of 1.5 times the hours defined as that period beginning at 12:00 midnight on Sunday and extended through 11:59 p.m. on Saturday. A non-exempt classfication shall be defined as being non-supervisory, non-administrative or non-professional within the terms of the Fair Labor Standards Act. It is to be expected by the administration of the Library District that all such overtime be held to an absolute minimum and must be approved in advance by the supervisor. Compensatory adjustments for overtime, whether taken as pay or compensatory time off shall be paid or taken within thirty days of accrual. An employee has the option to refuse overtime except in the case of an emergency situation.