version for 6

countdown/addon.setup.php

@@ -0,0 +1,12 @@
+<?php
+
+return [
+    'author'            => 'Jack McDade, EEHarbor',
+    'author_url'        => 'https://eeharbor.com/',
+    'name'              => 'Countdown',
+    'description'       => 'Countdown plug-in allows you to insert a simple countdown to a specified date into your templates.',
+    'version'           => '1.0.0',
+    'namespace'         => 'EEHarbor\Countdown',
+    'settings_exist'    => false,
+    // Advanced settings
+];

countdown/index.html

@@ -0,0 +1 @@
+Directory access is forbidden.

countdown/pi.countdown.php

@@ -0,0 +1,40 @@
+<?php
+
+if (! defined('BASEPATH')) {
+    exit('No direct script access allowed');
+}
+
+class Countdown
+{
+    public $return_data = "";
+
+    public function __construct()
+    {
+		$day = ee()->TMPL->fetch_param('day');
+		$month = ee()->TMPL->fetch_param('month');
+		$year = ee()->TMPL->fetch_param('year');
+		$hour = ee()->TMPL->fetch_param('hour');
+
+		// get current unix timestamp
+		$today = time();
+
+		//make unix timestamp for given date
+		$countdowndate = mktime(0, 0, $hour, $month, $day, $year);
+
+		//calculate difference  
+		$difference = $countdowndate - $today;
+		$difference = $difference < 0 ? 0 : $difference;
+
+		$days_left = floor($difference/60/60/24);
+		$hours_left = floor(($difference - $days_left*60*60*24)/60/60);
+
+		$variables = array();
+		$variables[] = array(
+			'days' => $days_left,
+			'hours' => $hours_left
+		);
+
+		$this->return_data = ee()->TMPL->parse_variables(ee()->TMPL->tagdata, $variables);
+        return $this->return_data;
+    }
+}