- function_exists: documentation ( source)
- date_default_timezone_set: documentation ( source)
- date: documentation ( source)
- strtotime: documentation ( source)
<?php
if (function_exists('date_default_timezone_set')) date_default_timezone_set('UTC');
$date = "30-12-1899 9:25:52 AM";
$date = strtotime($date);
echo date('Y-m-d H:i:s', $date);