If you want to do it without using any modules, and you want the m/d/y (or d/m/y, season to taste) format,

# Assuming you've got $timeval from a stat() call or some such
my ($d,$m,$y) = (localtime($timeval))[3,4,5];
my $mdy = sprintf '%d/%d/%d', $m+1, $d, $y+1900;
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