Link post dates to their archives in WordPress. Source: http://justintadlock.com/archives/2010/08/06/linking-post-published-dates-to-their-archives

link-post-dates.php

<?php

function prefix_link_post_dates() {
    
    /* Get the year, month, and day of the current post. */
    $year = get_the_time('Y');
    $month = get_the_time('m');
    $day = get_the_time('d');
    $out = '';
    
    /* Add a link to the monthly archive. */
    $out.= '<a href="' . get_month_link($year, $month) . '" title="Archive for ' . esc_attr(get_the_time('F Y')) . '">' . get_the_time('F') . '</a>';
    
    /* Add a link to the daily archive. */
    $out.= ' <a href="' . get_day_link($year, $month, $day) . '" title="Archive for ' . esc_attr(get_the_time('F d, Y')) . '">' . $day . '</a>';
    
    /* Add a link to the yearly archive. */
    $out.= ', <a href="' . get_year_link($year) . '" title="Archive for ' . esc_attr($year) . '">' . $year . '</a>';
    
    return $out;
}

add_shortcode('post_date_links', 'prefix_link_post_dates');