one event example of iCalendar implementation in PHP

iCalendar php

<?php    
    function escapeString($string) {
        return preg_replace('/([\,;])/','\\\$1', $string);
    }
    function dateToCal($timestamp) {
        return date('Ymd', $timestamp) .'T'. date('His', $timestamp) . "Z";
    }

    $eol = "\r\n";

    $load = "BEGIN:VCALENDAR" . $eol .
    "VERSION:2.0" . $eol .
    "PRODID:-//project/author//NONSGML v1.0//EN" . $eol .
    "CALSCALE:GREGORIAN" . $eol .
    "BEGIN:VEVENT" . $eol .
    "DTSTAMP:" . dateToCal(time()) . $eol .
    "DTSTART:" . dateToCal($from_timestamp) . $eol .
    "DTEND:" . dateToCal($till_timestamp) . $eol .
    "UID:" . $uid . $eol .
    "DESCRIPTION:" . htmlspecialchars($description) . $eol .
    "URL;VALUE=URI:" . htmlspecialchars($shortUrl) . $eol .
    "SUMMARY:" . htmlspecialchars($title) . $eol .
    "END:VEVENT" . $eol .
    "END:VCALENDAR";

    $filename="Event-".$title_no_space . ".ics";

    // Set the headers
    header('Content-type: text/calendar; charset=utf-8');
    header('Content-Disposition: attachment; filename=' . $filename);

    // Dump load
    echo $load;
?>