Show post's published and last updated (if different from published date) in human time in Genesis. Details: http://sridharkatakam.com/using-human-time-last-updated-date-genesis/

functions.php

<?php
//* Do NOT include the opening php tag

//* Create a shortcode to display published date's human time
add_shortcode('post_date_human', 'set_post_date_human');
function set_post_date_human($atts) {
  return human_time_diff( get_the_time('U'), current_time('timestamp') );
}

//* Create a shortcode to display last updated date's human time
add_shortcode('post_updateddate_human', 'set_last_updated_date_human');
function set_last_updated_date_human($atts) {
	return human_time_diff( the_modified_date('U','','',false), current_time('timestamp') );
}

//* Customize the entry meta in the entry header (requires HTML5 theme support)
add_filter( 'genesis_post_info', 'sk_post_info_filter' );
function sk_post_info_filter($post_info) {
	$post_info = 'Posted [post_date_human] ago by [post_author_posts_link] [post_comments] [post_edit]';
	if (get_the_modified_time() != get_the_time()) {
		$post_info = $post_info . '<br/>Last updated [post_updateddate_human] ago';
	}
	return $post_info;
}