According to conventional wisdom, TV shows that air at 8 00 p.m. are expected to perform poorly in the summer time because of the longer daily hours. But that theory flies in the face of the fact that CBS's 60 Minutes, which airs at 7 00 p.m. (primetime begins an hour earlier on Sundays than it does during the rest of the week) nearly always is one of the top-rated shows of the week during the summer, even while airing mostly repeats. Sunday night was no exception, as the veteran magazine show attracted 8.82 million viewers and was easily the top-rated program of the night. Moreover, Big Brother , which followed at 8 00 p.m., held on to most of that audience with 8.06 million viewers, a season high. ABC took over the lead at 9 00 p.m. with The Bachelorette Men Tell All , which drew 5.11 million viewers. But the other two networks, NBC and Fox, might have been cable channels, given the size of the audiences for some of their programs.