PHP date showing '1970-01-01 ' after conversion

Question

I have a form in which date format is dd/mm/yyyy . For searching database , I hanverted the date format to yyyy-mm-dd . But when I echo

Answer 1

Replace / with -:

$date1 = strtr($_REQUEST['date'], '/', '-');
echo date('Y-m-d', strtotime($date1));

Answer 2

Use below code for php 5.3+:

$date = new DateTime('1900-02-15');
echo $date->format('Y-m-d');

Use below code for php 5.2:

$date = new DateTime('1900-02-15');
echo $date->format('Y-m-d');