Chronos failures add months tesst.

chronos_fail_add_months.php

<?php
/**
 * @url http://scriptworks.jp/blog/2011/12/how_to_avoid_pitfall_of_php_datetime/ 
 */
require 'vendor/autoload.php';
use Cake\Chronos\Date;

$today = new Date('2011-01-31');
echo $today . PHP_EOL;
echo $today->modify('+1 months') . PHP_EOL;

// 2011-01-31
// 2011-03-03

$today2 = new Date('2011-03-31');
echo $today2 . PHP_EOL;
echo $today2->modify('-1 months') . PHP_EOL;

// 2011-03-31
// 2011-03-03