gistfile1.PL

#!/usr/bin/env perl
use strict;
use warnings;
use Schedule::Cron;
use Net::Twitter::Lite;

my $cron = Schedule::Cron->new( sub {} );
$cron->add_entry( '0 0-23 * * *', \&twit );
$cron->run( detach => 0 );

sub twit {
    my $t = Net::Twitter::Lite->new ( username => 'user', password => 'pass' );
    $t->update( scalar localtime() );
}