8If any officer was temporarily absent from his employment during the late war whilst serving in His Majesty's forces, or the forces of the Allied or Associated Powers, either compulsorily or with the sanction or permission of the local authority, such period of temporary absence shall be reckoned as service under the authority in whose employment he was immediately before and after such temporary absence:
Provided that in the case of an officer who, after the armistice, voluntarily extended his term of service in the forces, no period of absence during any such extension shall be reckoned.