At all elections, the polls shall be open at each polling place at 6:00 a.m. on the day of the election and closed at 7:00 p.m. on the same day except as provided for central absentee voter precincts pursuant to subsection G of § 24.2-712. At 6:45 p.m. an officer of election shall announce that the polls will close in fifteen minutes. The officers of election shall list the names of all qualified voters in line before the polling place at 7:00 p.m. and permit those voters and no others to vote after 7:00 p.m.