#! /usr/bin/perl

use strict;
use warnings;

my $var =  -440;
print "renee:\t ",clock_renee($var),"\n";
print "silbersteine: ",clock_silbersteine($var),"\n";

sub clock_renee {
    my $minutes = shift;
    my $hh = int $minutes/60;
    $minutes *=  -1 if($minutes < 0);
    my $rest = $minutes % 60;
    $rest = sprintf("%02d",$rest);
    return "$hh:$rest";
}

sub clock_silbersteine{
    my $minutes = shift;
    my $hh = int($minutes/60);
    my $rest = $minutes - $hh*60;
    if (length($rest) == 1) {$rest = "0".$rest}
    return "$hh:$rest";
}