http://apps.marudot.com/ical/

How to create an outlook calendar meeting request in PHP

http://r2d2.cc/2014/01/27/create-outlook-meeting-request-php/

http://stackoverflow.com/questions/5990017/add-events-to-outlook-calendar-with-php-script?rq=1

http://stackoverflow.com/questions/9356762/sending-outlook-ical-message-with-html-table?rq=1

http://fotan.us/create-calendar-ics-files-with-php/

http://www.julian-young.com/2009/07/07/php-ical-email/

Ymd\THis\Z  UTC

http://www.luc-sanchez.fr/2014/11/generer-un-evenement-ical-dans-outlook-en-php/#.VQcxu_mG9iw

https://www.exchangecore.com/blog/sending-outlookemail-calendar-events-php/