calitem.php

<?php
  $start = $_GET['start'];
  $end   = $_GET['end'];
  $sub   = $_GET['sub'];
  $desc   = $_GET['desc'];
  $loc   = $_GET['loc'];

$uid = md5(uniqid(mt_rand(), true)) . "duvallchamber.com";
$dtstamp =gmdate('Ymd').'T'. gmdate('His') . "Z";
$dtstart =date('Ymd',$start)."T".date('His',$start);

if ($end==''){
$dtend =date('Ymd',strtotime('+1 day',$start))."T".date('His',$start);
}
else
{
$dtend =date('Ymd',$end)."T".date('His',$end);
}
  
$ical = "BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//hacksw/handcal//NONSGML v1.0//EN
BEGIN:VEVENT
UID:" .$uid."
DTSTAMP:" .$dtstamp. "
DTSTART:".$dtstart."
DTEND:".$dtend."
SUMMARY:".$sub."
DESCRIPTION: https://duvallchamberofcommerce.com/duvall-events/#!event/".$desc."
LOCATION:".$loc."
END:VEVENT
END:VCALENDAR";

 //set correct content-type-header
 header('Content-type: text/calendar; charset=utf-8');
 header('Content-Disposition: inline; filename=calendar.ics');
 echo $ical;
 exit;
?>