title: Issue when updating date in db table
body: <p>I'm working on a codeigniter project and I'm trying to troubleshoot a sql issue. I have a query that updates a date field in my table and it's not updating it at all.</p>
  
  <p>I have this table</p>
  
  <pre><code>CREATE TABLE `Customer` (
    `customer_id` int(11) unsigned NOT NULL AUTO_INCREMENT,
    `first_name` varchar(55) NOT NULL DEFAULT '',
    `last_name` varchar(55) NOT NULL DEFAULT '',
    `city` varchar(255) DEFAULT '',
    `state` char(2) DEFAULT '',
    `zip` int(5) DEFAULT NULL,
    `title` varchar(255) NOT NULL DEFAULT '',
    `image` varchar(255) DEFAULT '',
    `blurb` blob,
    `end_date` date DEFAULT NULL,
    `goal` int(11) DEFAULT NULL,
    `paypal_acct_num` int(11) DEFAULT NULL,
    `progress_bar` enum('full','half','none') DEFAULT NULL,
    `page_views` int(11) NOT NULL DEFAULT '0',
    `total_pages` int(11) NOT NULL DEFAULT '0',
    `total_conversions` int(11) NOT NULL DEFAULT '0',
    `total_given` int(11) NOT NULL DEFAULT '0',
    `conversion_percentage` int(11) NOT NULL DEFAULT '0',
    `avg_contribution` int(11) NOT NULL DEFAULT '0',
    PRIMARY KEY (`customer_id`)
  ) ENGINE=MyISAM AUTO_INCREMENT=15 DEFAULT CHARSET=utf8;
  </code></pre>
  
  <p>and when I run this query to insert data, it runs fine and sets the date to <code>2012-11-01</code></p>
  
  <pre><code>INSERT INTO `Customer` (`first_name`, `last_name`, `end_date`) VALUES ('John', 'Smith2', '2012-11-01');
  </code></pre>
  
  <p>Then I get the customer_id and try to run this query</p>
  
  <pre><code>UPDATE `Customer` SET `end_date` = '2012-14-01' WHERE `customer_id` = '18';
  </code></pre>
  
  <p>and it sets the date end_date field to <code>0000-00-00</code>. </p>
  
  <p>Why is it changing the end date to 0000-00-00 rather than 2012-14-01?</p>