How to add ‘Last updated on: date’ to post info in Genesis

//* Add support for custom header
add_theme_support( 'custom-header', array(
'width' => 320,
'height' => 60,
'header-selector' => '.site-title a',
'header-text' => false
) );

//* Add support for structural wraps
add_theme_support( 'genesis-structural-wraps', array(
'header',
'site-tagline',
'nav',
'subnav',
'home-featured',
'site-inner',
'footer-widgets',
'footer',
'featured'
) );

// Changing excerpt more
function new_excerpt_more($more) {
global $post;
return '…ID) . '">' . ' Read More »' . '';
}
add_filter('excerpt_more', 'new_excerpt_more');

/***************
*
* End of Edit by Jeff
*
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//* Add support for 3-column footer widgets
add_theme_support( 'genesis-footer-widgets', 3 );

//* Unregister layout settings
genesis_unregister_layout( 'content-sidebar-sidebar' );
genesis_unregister_layout( 'sidebar-content-sidebar' );
genesis_unregister_layout( 'sidebar-sidebar-content' );

//* Unregister secondary sidebar
unregister_sidebar( 'sidebar-alt' );

//* Create portfolio custom post type
add_action( 'init', 'minimum_portfolio_post_type' );
function minimum_portfolio_post_type() {

register_post_type( 'portfolio',
array(
'labels' => array(
'name' => __( 'Portfolio', 'minimum' ),
'singular_name' => __( 'Portfolio', 'minimum' ),
),
'exclude_from_search' => true,
'has_archive' => true,
'hierarchical' => true,
'menu_icon' => get_stylesheet_directory_uri() . '/images/icons/portfolio.png',
'public' => true,
'rewrite' => array( 'slug' => 'portfolio' ),
'supports' => array( 'title', 'editor', 'author', 'thumbnail', 'excerpt', 'trackbacks', 'custom-fields', 'comments', 'revisions', 'page-attributes', 'genesis-seo' ),
)
);

}

//* Remove site description
remove_action( 'genesis_site_description', 'genesis_seo_site_description' );

//* Reposition the primary navigation menu
remove_action( 'genesis_after_header', 'genesis_do_nav' );
add_action( 'genesis_after_header', 'genesis_do_nav', 15 );

//* Reposition the secondary navigation menu
remove_action( 'genesis_after_header', 'genesis_do_subnav' );
add_action( 'genesis_footer', 'genesis_do_subnav', 7 );

//* Reduce the secondary navigation menu to one level depth
add_filter( 'wp_nav_menu_args', 'minimum_secondary_menu_args' );
function minimum_secondary_menu_args( $args ){

if( 'secondary' != $args['theme_location'] )
return $args;

$args['depth'] = 1;
return $args;

}

//* Add the site tagline section
function minimum_site_tagline() {

printf( '', genesis_attr( 'site-tagline' ) );
genesis_structural_wrap( 'site-tagline' );

printf( '', genesis_attr( 'site-tagline-left' ) );
printf( '%s', genesis_attr( 'site-description' ), esc_html( get_bloginfo( 'description' ) ) );
echo '';

printf( '', genesis_attr( 'site-tagline-right' ) );
genesis_widget_area( 'site-tagline-right' );
echo '';

genesis_structural_wrap( 'site-tagline', 'close' );
echo '';

}

//* Modify the size of the Gravatar in the author box
add_filter( 'genesis_author_box_gravatar_size', 'minimum_author_box_gravatar' );
function minimum_author_box_gravatar( $size ) {

return 144;

}

//* Modify the size of the Gravatar in the entry comments
add_filter( 'genesis_comment_list_args', 'minimum_comments_gravatar' );
function minimum_comments_gravatar( $args ) {

$args['avatar_size'] = 96;
return $args;

}

//* Change the number of portfolio items to be displayed (props Bill Erickson)
add_action( 'pre_get_posts', 'minimum_portfolio_items' );
function minimum_portfolio_items( $query ) {

if ( $query->is_main_query() && !is_admin() && is_post_type_archive( 'portfolio' ) ) {
$query->set( 'posts_per_page', '6' );
}

}

//* Register widget areas
genesis_register_sidebar( array(
'id' => 'site-tagline-right',
'name' => __( 'Site Tagline Right', 'minimum' ),
'description' => __( 'This is the site tagline right section.', 'minimum' ),
) );
genesis_register_sidebar( array(
'id' => 'home-featured-1',
'name' => __( 'Home Featured 1', 'minimum' ),
'description' => __( 'This is the home featured 1 section.', 'minimum' ),
) );
genesis_register_sidebar( array(
'id' => 'home-featured-2',
'name' => __( 'Home Featured 2', 'minimum' ),
'description' => __( 'This is the home featured 2 section.', 'minimum' ),
) );
genesis_register_sidebar( array(
'id' => 'home-featured-3',
'name' => __( 'Home Featured 3', 'minimum' ),
'description' => __( 'This is the home featured 3 section.', 'minimum' ),
) );
genesis_register_sidebar( array(
'id' => 'home-featured-4',
'name' => __( 'Home Featured 4', 'minimum' ),
'description' => __( 'This is the home featured 4 section.', 'minimum' ),
) );

//* Register widget area
genesis_register_sidebar( array(
'id' => 'featured',
'name' => __( 'Featured', 'minimum' ),
'description' => __( 'This is the featured section.', 'minimum' ),
) );

/***************
*
* Edited by Jeff
*
****************/

//* Add last updated date to the post info in entry header (requires HTML5 theme support)
add_filter( 'genesis_post_info', 'sk_post_info_filter' );
function sk_post_info_filter($post_info) {

if (get_the_modified_time() != get_the_time()) {
$post_info = $post_info . 'Last updated on: ' . the_modified_date('F j, Y', '', '', false);
}
return $post_info;

}

/***************
*
* End Edit
*
****************/

//* Add the featured section
add_action( 'genesis_after_header', 'sk_featured' );
function sk_featured() {

if ( is_active_sidebar( 'featured' ) ) {

printf( '', genesis_attr( 'featured' ) );
genesis_structural_wrap( 'featured' );

genesis_widget_area( 'featured' );

genesis_structural_wrap( 'featured', 'close' );
echo '';

}