Create .ics Calendar Event in Visualforce

vCalendarPage.html

<!--
  Simple proof-of-concept to create a .ics calendar event with visualforce.
  Inspired by Natalie Regier @gnatrae

  This example uses url parameters to set the details of event.
  You could create a custom button that invokes this page, like:
  https://<your-salesforce-domain>/apex/vCalendarPage?start={!TEXT(Obj.StartDate__c)}&end={!TEXT(Obj.EndDate__c)}&subject=Event from Visualforce&description=This .ics event created with visualforce&location=The Cloud
  
  An example with literal values you can copy & paste in your browser:
  https://<your-salesforce-domain>/apex/vCalendarPage?start=20140524T140000&end=20140524T153000&subject=Event from Visualforce&description=This .ics event created with visualforce&location=The Cloud
-->
<apex:page title="event.ics" contentType="text/calendar" cache="false">
BEGIN:VCALENDAR
VERSION:2.0
PRODID::-//hacksw/handcal//NONSGML v1.0//EN
BEGIN:VEVENT
DTSTAMP;TZID=GMT:<apex:outputText value="{!SUBSTITUTE(SUBSTITUTE(SUBSTITUTE($CurrentPage.parameters.start,':',''),'-',''),' ','T')}"/>
UID:<apex:outputText value="{!SUBSTITUTE(SUBSTITUTE(SUBSTITUTE($CurrentPage.parameters.start,':',''),'-',''),' ','')}"/>[email protected]
DTSTART;TZID=GMT:<apex:outputText value="{!SUBSTITUTE(SUBSTITUTE(SUBSTITUTE($CurrentPage.parameters.start,':',''),'-',''),' ','T')}"/>
DTEND;TZID=GMT:<apex:outputText value="{!SUBSTITUTE(SUBSTITUTE(SUBSTITUTE($CurrentPage.parameters.end,':',''),'-',''),' ','T')}"/>
SUMMARY:<apex:outputText value="{!$CurrentPage.parameters.subject}"/>
DESCRIPTION:<apex:outputText value="{!$CurrentPage.parameters.description}"/>
LOCATION:<apex:outputText value="{!$CurrentPage.parameters.location}"/>
END:VEVENT
END:VCALENDAR
</apex:page>

Check out my new blog post for a solution that does not require Visualforce or attachments, https://douglascayers.com/2019/06/22/how-to-send-google-and-outlook-calendar-invite-links-in-email-templates/

@douglascayers Following up on this, it appears that the link that you posted above is broken. Do you happen to have that article somewhere? I'm very interested in learning how you did it.

@douglascayers Can we provide the latest link as existing link is not working.