A teacher being a member of The Manitoba Teachers' Society Executive Committee, or of the Executive Committee of any branch thereof, or any special committee of the Society or being appointed an official representative or delegate of the Society or any branch thereof, and being authorized by the Executive Committee of which that teacher is member, or acting as a representative or delegate, shall be excused from College duties for either purpose or both purposes for not more than a total of five (5) teaching days in any one school year, provided, that a substitute satisfactory to the Institute can be secured, and that the cost of providing such substitute is assumed by the Society/Local Association. A maximum of fifteen (15) days in total may be taken for the purposes mentioned above during any school year by members of the association. No additional leave of absence beyond fifteen (15) days in a College year shall be taken for the purposes mentioned above except with the consent and approval of the Institute. In all cases the teacher shall notify the Institute a minimum of five (5) teaching days prior to taking such leave.