Guidance counsellors who have a full-time counselling position in a high school the following year may be employed during the Summer Vacation to assist with timetable changes for students for up to five (5) days as assigned by the principal. Such employment shall be voluntary on the part of the counsellor. Guidance counsellors shall receive during the following school year compensatory time equal to the number of days employed during July and August. The method and timing of such compensatory time shall be mutually agreed to by the principal and the counsellor. The details of such arrangements shall be subject to the prior approval of the Superintendent.