date('Y-m-d H:i:s')
<?php echo "Today is " . date("Y/m/d") . "<br>"; echo "Today is " . date("Y.m.d") . "<br>"; echo "Today is " . date("Y-m-d") . "<br>"; echo "Today is " . date("l"); ?>
<?php $d=mktime(11, 14, 54, 8, 12, 2014); echo "Created date is " . date("Y-m-d h:i:sa", $d); ?>
date("Y-m-d H:i:s");
echo date('c'); // 2015-07-27T00:00:00+02:00