Conditional cache-busting for WordPress stylesheets

conditional-cache-buster.php

// Tired of making changes to your WordPress site's stylesheet, only to have the client tell you "It looks the same to me!"?
// Force WordPress to send a fresh copy to logged-in users with this simple code snippet.
// (In practice, put this code in your WordPress theme (e.g., in functions.php) or in a custom plugin.)
$now = new DateTime();
$now_version = $now->format('YmdHis');
if (is_user_logged_in()) {
  wp_enqueue_style( 'pacificbiosciences-style', get_stylesheet_uri(), array(), $now_version );
} else {
  wp_enqueue_style( 'pacificbiosciences-style', get_stylesheet_uri() );
}