nigel@freud:~$ cat /usr/local/bin/puppetwhen 
#!/usr/bin/perl

use strict;
use warnings;

use YAML;
use Date::Parse;

my %nodes;
foreach my $file ( glob '/var/lib/puppet/yaml/facts/*.yaml' ) {
    my $data = YAML::LoadFile($file);

    my $name = $data->{name};
    my $age = time - str2time($data->{version});
    $age = int($age/60 + 0.5);

    $nodes{$name} = $age;
}  

my @sorted = sort { $nodes{$a} <=> $nodes{$b} } keys %nodes;
foreach my $key (@sorted) {
    printf("%5d minutes ago: %s\n", $nodes{$key}, $key);
}