ISO 8601 php

//Object Oriented Method

$datetime = new DateTime('2010-12-30 23:21:46');

echo $datetime->format(DateTime::ATOM); // Updated ISO8601


//Procedural Method

echo date(DATE_ISO8601, strtotime('2010-12-30 23:21:46'));/**
 * Its always best to use a datetime object
 */
$dateTime = new \DateTime();
/**
 * You can get the string by using format
 */
$dateTime->format('Y-m-d H:i:s');FYI: there's a list of constants with predefined formats on the DateTime object, for example instead of outputting ISO 8601 dates with:

<?php
echo date('c');
?>

or

<?php
echo date('Y-m-d\TH:i:sO');
?>

You can use

<?php
echo date(DateTime::ISO8601);
?>

instead, which is much easier to read.
$dateTime = new \DateTime();
$dateTime->format('Y-m-d H:i:s');