#!/usr/bin/perl -w

use strict;

my @test=(	"example: 10/29/2001",
		"example: 2/18/2000 3rd quarter",
		"example: 3/18/2000 4th quarter",
		"example: 4/18/2000 4th quarter",
		"example: 5/18/2000 4th quarter",
		"example: 6/18/2000 1st quarter",
		"example: 7/18/2000 1st quarter",
		"example: 11/18/2001 2nd quarter",
		"example: 01/18/1999 3rd quarter",
		"example: 02/18/1999 3rd quarter",
		"example: 3/18/1999 4th quarter",
		"example: 4/18/1999 4th quarter",
		"example: 5/18/1999 4th quarter",
		"example: 6/18/1999 1 quarter",
		"example: 7/18/1999 1 quarter",
		"example: 8/18/1999 1 quarter",
		"example: 9/18/1999 2nd quarter",
		"example: 10/18/1999 2nd quarter",
		"example: 11/18/1999 2nd quarter",
		"example: 12/18/1999 3rd quarter"
	);

sub my_compare(){
	# use "our" to limit scope to function but persist
	# map months to quarters
	our %quarters=(
		'6'=> 1,
		'06'=> 1,
		'7'=> 1,
		'07'=> 1,
		'8'=> 1,
		'08'=> 1,
		'9'=> 2,
		'09'=> 2,
		'10'=> 2,
		'11'=> 2,
		'12'=> 3,
		'1'=> 3,
		'01'=> 3,
		'2'=> 3,
		'02'=> 3,
		'3'=> 4,
		'03'=> 4,
		'4'=> 4,
		'04'=> 4,
		'5'=> 4,
		'05'=> 4
	    );

# $a  and $b are given to us by sort
# they are the left & right sides of the comparision
# 
	my ($mon, $day);

	$a=~m|(\d*)/(\d*)/(\d*)|;
	$mon=length($1)<2?'0'.$1:$1;
	$day=length($2)<2?'0'.$2:$2;
	my $a3=$3 . $quarters{$mon}.$mon .$day;		
	die "bad year in $a" unless length ($3)==4;

	$b=~m|(\d*)/(\d*)/(\d*)|;
	$mon=length($1)<2?'0'.$1:$1;
	$day=length($2)<2?'0'.$2:$2;
	my $b3=$3 . $quarters{$mon}. $mon .$day;
	die "bad year in $b" unless length ($3)==4;

	return $a3 <=> $b3;
}

@test=sort(my_compare(), @test);
print join "\n", @test;