Human Time Difference Function for WordPress

wp_human_time_diff.php

<?php
/**
 * Display the post time in a human readable format
 *
 * @return string
 */
function carmack_human_time_diff() {

	$post_time = get_the_time( 'U' );
	$time_now = date( 'U' );

	// Use human time if less that 60 days ago, otherwise display the date
	// Uses the WordPress internal function human_time_diff
	// 60 seconds * 60 minutes * 24 hours * 90 days.
	if ( $post_time > $time_now - ( 60 * 60 * 24 * 90 ) ) {
		$human_time = sprintf( esc_html__( '%s ago', 'carmack' ), human_time_diff( $post_time, current_time( 'timestamp' ) ) );
	} else {
		$human_time = get_the_date();
	}

	$human_time = sprintf( '<span class="post-human-time">%s</span>', $human_time );

	return $human_time;

}