Possible pure Perl solution...

my $wday = (localtime)[6];
my $offset = $wday == 1 ? 3 : ($wday == 0 ? 2 : 1);
my @date = localtime(time - 86400*$offset);
printf "%s-%s-%s\n", 1900+$date[5], 1+$date[4], $date[3];
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Doesn't take into account holidays, just weekends.