my $best = undef;
for (@returns)
{
    my $diff = abs($ctime - $_);
    unless (defined $best)
    {
        $best = [$_, $diff];
        next;
    }

    if ($diff < $best)
    {
        $best = [$_, $diff];
        next;
    }

    if ($diff > $best)
    {
        last;
    }
}

print "Best match is $best->[0] at $best->[1] away from $ctime\n";