Ref: OM19 / DECOM-8

Is your feature request related to a problem? Please describe.

As a visitor for adding a meeting to my personal calendar I find the process too manual and error prone: I need to find the datetime at my calendar, add the title, location, etc.

Describe the solution you'd like

For this problem other platforms (like Eventbrite, see "Additional context") choose ways to adding to the most popular calendar software.

It also exists the .ICS standard format (that we already send attached to an inscription of the meeting).

Describe alternatives you've considered

For technological sovereignty we could only allow the .ICS format download, but most people don't know what that means. It's a political vs usability trade-off :/

Additional context

Metadecidim proposal

For instance, an event in Eventbrite:

Every option has this logic.

• Outlook calendar: download .ICS
• Google calendar: generates this URL. It opens a new window with the event details (title, start and end date and time, description and location) already filled in
• Apple calendar: download .ICS
• Yahoo calendar: generates another URL

In the case of Google calendar this is the parameters of the URL:

https://calendar.google.com/calendar/u/0/r/eventedit?text=TITLE&dates=START_DATETIME/END_DATETIME&details=DESCRIPTION&location=LOCATION&sf=true

Where DESCRIPTION is "For full details go to (Decidim URL)"

Does this issue could impact on users private data?
No, we're talking about personal calendar software but it's only importing an already created meeting.

Acceptance criteria

• As a visitor I have the "Add to calendar" option
• When I click this option I can "Add to Outlook calendar" and download an .ICS
• When I click this option I can "Add to Apple calendar" and download an .ICS
• When I click this option I can "Add to Google calendar" and get a new window with the form to add the event in my calendar already filled in