Section 9. In any city or town accepting the provisions of this section and notwithstanding any other provision of this chapter to the contrary, any excise due under this chapter by a member of the Massachusetts National Guard or reservist or a dependent of a member of the Massachusetts National Guard or reservist shall be deferred while that member is on active service outside the commonwealth and for a period of up to 180 days after completion of that service. No interest or penalties shall be assessed for any period before the expiration of the 180 days.