PHP convert date format dd/mm/yyyy => yyyy-mm-dd

Here's another solution not using date(). not so smart:)

$var = '20/04/2012';
echo implode("-", array_reverse(explode("/", $var)));

Dates in the m/d/y or d-m-y formats are disambiguated by looking at the separator between the various components: if the separator is a slash (/), then the American m/d/y is assumed; whereas if the separator is a dash (-) or a dot (.), then the European d-m-y format is assumed. Check more here.

Use the default date function.

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

EDIT I just tested it, and somehow, PHP doesn't work well with dd/mm/yyyy format. Here's another solution.

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

Try Using DateTime::createFromFormat

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

Output

2012-04-24

EDIT:

If the date is 5/4/2010 (both D/M/YYYY or DD/MM/YYYY), this below method is used to convert 5/4/2010 to 2010-4-5 (both YYYY-MM-DD or YYYY-M-D) format.

$old_date = explode('/', '5/4/2010'); 
$new_data = $old_date[2].'-'.$old_date[1].'-'.$old_date[0];

OUTPUT:

2010-4-5