https://dcblog.dev/adding-events-to-microsoft-outlook-from-php-using-ical

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

php add event to outlook calendar

https://github.com/iarvindverma/OutlookEventMailPhp

https://stackoverflow.com/questions/12776088/how-to-create-an-outlook-calendar-meeting-request-in-php

https://arvindverma.com/create-and-send-outlook-meeting-calendar-event-using-php/

vcalendar

https://www.luc-sanchez.fr/2014/11/generer-un-evenement-ical-dans-outlook-en-php/#.XmgTH6hKhaQ

https://caillaud.fr/creer-un-fichier-icalendar-ics-en-php/

https://openclassrooms.com/forum/sujet/invitation-outlook-fichier-ics-en-php

https://fr.wikipedia.org/wiki/ICalendar