This post converting the MySql date format to xml date time format in php.

1. Code:

    <?php 	
	function convertMySqlDateToXmlDate($mySqlDate, $gmtOffset = "+00:00"){
		$d = mySqlStringDate2String($mySqlDate, "Y-m-d");
		$t = mySqlStringDate2String($mySqlDate, "H:i:s");
		return $d . "T" . $t . $gmtOffset;
	}
	function mySqlStringDate2String($mysqlDateStr, $format){
		if (is_null($mysqlDateStr) || trim($mysqlDateStr) == '' || "0000-00-00 00:00:00" == trim($mysqlDateStr)) {
			return null;
		}
		try {
    		$d = date_create_from_format('Y-m-d H:i:s', $mysqlDateStr);
    		if (false === $d) {
    			throw new \Exception ("Invalid date");
    		}
		}catch (\Exception $e) {
		    return $mysqlDateStr;
		}
		$str = $d->format($format);
		return (false != $str) ? $str : null;
	}
	
	$str = "2018-11-15 00:00:00";	
	echo(convertMySqlDateToXmlDate($str));
    ?> 

2. Example:

Input:

"2018-11-15 00:00:00"

Output:

2018-11-15T00:00:00+00:00