Boards of voter registration and elections shall remain open as provided by law and, in addition thereto, shall remain open and available for registration on any additional days, during such hours and at such various places throughout the county as the boards may determine. Such boards also shall remain open and available for absentee registration and absentee voting responsibilities during such additional hours as the boards may deem necessary. Notice of the time and place shall be given by prior publication in a newspaper of general circulation in the county.