It's not a big deal, but if it were me, I wouldn't want to pollute my code with a bunch of unnecessary lexicals. I prefer to use array slices. So those two localtime calls would become:

    my $wday = (localtime $now)[6];

    ....

    my($mday, $mon, $year) = (localtime($now-$then))[3..5];
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Which, in my opinion, is cleaner.