mpchadwick/zend-date-issue.php

## zend-date-issue.php
<?php

// Replace this with whatever you need to initialize Magento
// this is really only needed to be able to instantiate a `Zend_Date` object
require_once('/var/www/html/app/Mage.php');
Mage::app();

$createdAt = '2016-01-03 05:01:24';
$timezone = 'America/New_York';

$date = new Zend_Date(strtotime($createdAt), null, 'en_US');
$date->setTimezone($timezone);
$date->setHour(0)->setMinute(0)->setSecond(0);

echo $date->get('YYYY-MM-dd') . PHP_EOL;
	<?php

	// Replace this with whatever you need to initialize Magento
	// this is really only needed to be able to instantiate a `Zend_Date` object
	require_once('/var/www/html/app/Mage.php');
	Mage::app();

	$createdAt = '2016-01-03 05:01:24';
	$timezone = 'America/New_York';

	$date = new Zend_Date(strtotime($createdAt), null, 'en_US');
	$date->setTimezone($timezone);
	$date->setHour(0)->setMinute(0)->setSecond(0);

	echo $date->get('YYYY-MM-dd') . PHP_EOL;