1. user inputs start month/day, end month/day;
2. randomly choose breakfast, lunch, dinner every day during that span.
3. save to file

I won't bore you with why he wanted this, but here's what I came up with:

#!/usr/bin/perl

use warnings;
use strict;

my %months = ( 1 => "Jan", 2 => "Feb", 3 => "Mar", 4 => "Apr", 5 => "M
+ay", 6 => "June", 7 => "July", 8 => "Aug", 9 => "Sept", 10 => "Oct", 
+11 => "Nov", 12 => "Dec" );

my @breakfast = qw/bagel cereal toast yogurt/;
my @lunch     = qw/sandwich milkshake pb&j hoagie/;
my @dinner    = qw/pasta rice chicken steak/;

my $file = '';
my ($start_day, $start_mon, $end_day, $end_mon);
my ($total, $len, $curr_mon, $curr_day);
my $three_one = join ('|', qw/1 3 5 7 8 10 12/); #months with 31 days
my $three_zero = join ('|', qw/4 6 9 11/); #months with 30 days

print "Enter start month (ie., for January, enter 1): ";
    chomp($start_mon = <STDIN>);
print "Enter start day (ie., 20): ";
    chomp($start_day = <STDIN>);
print "Enter end month (ie., for March, enter a 3): ";
    chomp($end_mon = <STDIN>);
print "Enter end day (ie., 21): ";
    chomp($end_day = <STDIN>);
print "Save to file [hit enter for default 'plan']: ";
    chomp($file = <STDIN>);
if($file eq '') {
    $file = "plan";
}

open(FH, ">$file") or die "open: $!\n";

$curr_mon = $start_mon;
$curr_day = $start_day;

$total = get_days(); # get # of days for the current month

while (1) {
    last if($curr_mon eq $end_mon && $curr_day == $end_day + 1);
    print FH "$months{$curr_mon} $curr_day\n";
    $len = length($months{$curr_mon}) + length($curr_day) + 1;
    print FH "-" x $len, "\n";

    print FH "Breakfast: ", $breakfast[ rand @breakfast], "\n";
    print FH "Lunch    : ", $lunch[ rand @lunch], "\n";
    print FH "Dinner   : ", $dinner[ rand @dinner], "\n";
    print FH "-" x $len, "\n";

    $curr_day++;
    if($curr_day > $total) {
        $curr_mon++;
        $curr_day = 1;
        $total = get_days();
    }
}
print "Written to file $file.\n";
close(FH);

sub get_days {
    if($curr_mon =~ /$three_one/) {
        return 31;
    } elsif($curr_mon =~ /$three_zero/) {
        return 30;
    } elsif($curr_mon == 2) {
        return 29;
    } else {
        die "Bad month entered!\n";
    }
}
[download]

It works fine - it just seems long and not very neat. I'm still a beginner and was wondering how more experienced monks might have written it.