Payment date column

I have made this code:

// Adding the date for column
function custom_shop_order_column($columns) {
  $columns['payment_date'] = __('P?atno??', 'kursysklepbs');
    return $columns;
}
add_filter('manage_edit-shop_order_columns', 'custom_shop_order_column', 11);

// Adding data for column
function custom_orders_list_column_content( $column ) {
  global $post, $woocommerce, $the_order;
    $order_id = $the_order->get_id();
  switch ( $column )
    {
      case 'payment_date' :
        $myVarOne = get_post_meta( $order_id, '_completed_date', true );
				echo substr($myVarOne, 0, -9);
        	break;
    }
}
add_action( 'manage_shop_order_posts_custom_column' , 'custom_orders_list_column_content', 10, 2 );

The only thing left is I would like this column to bee sortable.

Finally my working code looks like:

// Adding column P?atno??
function custom_shop_order_column($defaults) {
  $defaults['payments'] = __('Payment', 'kursymemobs');
    return $defaults;
}
add_filter('manage_edit-shop_order_columns', 'custom_shop_order_column', 11 );

// Adding data for column P?atno??
function custom_orders_list_column_content( $column ) {
  global $post, $woocommerce, $the_order;
    $order_id = $the_order->get_id();
  switch ( $column )
    {
      case 'payments' :
        $myVarOne = get_post_meta( $order_id, '_completed_date', true );
				echo substr($myVarOne, 0, -9);
        	break;
    }
}
add_action( 'manage_shop_order_posts_custom_column' , 'custom_orders_list_column_content', 10, 2 );

//Make column P?atno?? sortable
function my_sortable_column( $columns ) {
    $columns['payments'] = 'modified';
    	return $columns;
}
add_filter( 'manage_edit-shop_order_sortable_columns', 'my_sortable_column' );

It works quite well.