Notwithstanding any provisions of Section 351 of the Code of Civil Procedure to the contrary, when summons may be personally served upon a person as provided in Sections 17459 and 17460, the time of his absence from this State is part of the time limited for the commencement of the action described in those sections, except when he is out of this State and cannot be located through the exercise of reasonable diligence, except this section in no event shall be applicable in any action or proceeding commenced on or before September 7, 1956.