It shall be the duty of the City to give notice to any owner or tenant of any such premises to remove snow and/or ice, which notice shall be sent by registered mail to the last known address of such owner, tenant or occupant; the tenant or owner shall have not more than 24 hours from and after receipt of such notice within which to remove the snow and/or ice as set forth in said notice. (1985 Code, § 12.04.020)