Section 31E. Notwithstanding any general or special law to the contrary, a state employee, during working hours and at such times as are approved by the employee's supervisor and under regulations promulgated hereunder, may, without loss of salary, provide voluntary services at a public elementary, secondary, or vocational-technical school to assist the improvement of a student's or school's educational program; provided, however, that said voluntary services do not exceed the equivalent of 1 work day per month. There shall be no requirement that the employee have a child as a student in the school or school district. Said services shall not be compensated by a school.