Wordpress: Last Updated On

functions.php

<?php
function display_last_updated_date( $content ) {
  $original_time = get_the_time('U');
  $modified_time = get_the_modified_time('U');
  
  if ($modified_time >= $original_time + 86400) {
    $updated_time = get_the_modified_time('h:i a');
    $updated_day = get_the_modified_time('F jS, Y');
    $modified_content .= '<p class="last-modified">This page was last updated on '. $updated_day . ' at '. $updated_time .'</p>';
}

  $modified_content .= $content;
  return $modified_content;
}
add_filter( 'the_content', 'display_last_updated_date' );

style.css

.last-modified{
    background-color: burlywood;
    color: black;
    text-transform: uppercase;
    font-size: 0.8em;
}