The county board of education shall have the authority, under the rules and regulations promulgated from time to time by the State Board of Education, to provide for leaves of absence and vacations by the employees of the boards and for the payment from public funds to the employees of the boards for leaves of absence or vacations, or both. The boards may provide leaves of absence during the times the schools are not in session for the teachers and employees on full pay when the teacher or employee devotes the leave of absence to instructing in or attending schools for teacher training or in the manner approved by the State Board of Education as beneficial to the educational work of the county and may also provide for the payment of any full-time teachers for absences during the time schools are in session where the absence results from sickness or some other unavoidable cause which prevents the teacher from discharging his or her duties. Notwithstanding the foregoing, any teacher not utilizing or being paid for the sick leave accrued in any one year pursuant to regulations of the State Department of Education may accumulate days at the rate of one day per month for the months employed and carry over the unutilized days to the next consecutive year or years of employment for the same school system, or for any other school system in which the educator may later be employed, until he or she shall accumulate the maximum number of days as provided in subsection (b) of Section 16-1-18.1. Pay for the absences resulting from unavoidable causes other than sickness shall not be allowed for a longer time than one week during any one year. The allowance of such pay shall at all times be in the discretion of the county board of education.