How compare custom fields date in wordpress? -

i doing task event management, have coded widget display coming or past events in sidebar, can not handle custom fields date. following code, while date being stored "m/d/y". please me resolve issue. in adance

$today = date('m/d/y');     $args = array(         'post_type' => 'event',         'post_status' => 'publish',         'meta_key' => 'event_date',         'posts_per_page' => '5',         'meta_query' => array(                                 array(                                     'key' => 'event_date',                                     'value' => $today,                                     'compare' => '<=',                                     'type' => 'date'                                 )         ),         'orderby' => 'meta_value_num',         'order' => 'asc'     );      $the_query = new wp_query( $args ); 

date must in yyyy-mm-dd format meta_query comparison work

$today = date("y-m-d");