dd-mm-yyyy to yyyy-mm-dd in php code example

Example 1: php convert date from dd/mm/yyyy to yyyy-mm-dd

$date = DateTime::createFromFormat('d/m/Y', "24/04/2012");
echo $date->format('Y-m-d');

Example 2: yyyymmdd to yyyy-mm-dd php

<?php
// both lines output 813470400
echo strtotime("19951012"), "\n",
     strtotime("12 October 1995");

// prints 1995 Oct 12
echo date("Y-m-d", strtotime("19951012"));
?>

Example 3: convert dd/mm/yyyy to yyyy-mm-dd in mysql php

$var = '20/04/2012';
$date = str_replace('/', '-', $var);
echo date('Y-m-d', strtotime($date));