#!/usr/bin/perl 
use warnings;
use strict;

use Tk;


my $mw = new MainWindow;
my $time;
my $label = $mw->Label(-textvariable => \$time);
$label->grid(-row => 1, -column => 1);

$mw->repeat(1000, sub {timer (\$time)});

MainLoop;


sub timer {
    my ($varRef) = @_;
    
    $$varRef = time();
}