$startdate = strtotime( get_post_meta( $post->ID, 'sub_seminars_0_Start_date', true ) );
$todaydate = time();

if( $todaydate > $startdate && !$startdate ){

    $del_data = array(
                    'Ref' => 'sub_seminars_0_ref',
                    'Start date' => 'sub_seminars_0_start_date',
                    'End Date' => 'sub_seminars_0_end_date',
                    'Venue' => 'sub_seminars_0_venue',
                    'Fees' => 'sub_seminars_0_fees',
                    'CPE Credits' => 'sub_seminars_0_cpe_credits'
        );

    delete_row('sub_seminars', 1, $post->ID);

    $row = count( get_field('sub_seminars', $post->ID) );

    if ($row == 0){

        wp_update_post(array(
            'ID'    =>  $post->ID,
            'post_status'   =>  'draft'
        ));

    }
}