Open .ics files with Windows 10 Calendar app

I am trying to add an appointment I have been sent via email to the calendar app.

What happened so far:

Windows 10 opens the attached .ics file with Outlook and proceeds to add it to one of the inactive calendars in there. I don't want to use Outlook (or any inactive calendars which don't sync).

I saved the .ics file on the desktop and tried to "open with" but found that "open with" doesn't give me the option to choose a random app or the calendar app but only Outlook, an assorted list of some applications including Notepad, and the Windows Store.

I tried to set a default for calendar in the Windows 10 "All settings" -> "Default apps" and found that no program is configured for "Calendar". When I try to configure one (the calendar app), it says it cannot find any suitable app on my PC and proceeds not to find a suitable app in the Store.

So I finally gave up and figured I ask someone.

Any ideas?

You can change the default app Settings > System > Default apps > Choose default apps by file type (on the bottom) for each extension, including .ics. I could see in the list The Calendar Windows App, and managed to open an .ics I had received.

Screenshots with Windows 10 Version 1909:

It seems that Windows 10 Calendar does support .ics files now.

I had an attachment on an email which was labelled "not supported calendar message.ics" - I clicked on it anyway - nothing seemed to happen.

So I imported the .ics file anyway as follows: I right clicked on the attachment and saved it to disk. I then right clicked on the .ics file and I selected "open with": and then Windows "Calendar" app from list. I opened Windows 10 Calendar and the entry was there. it was actually there twice since the first click worked anyway, just no notification so I did not know it worked

I don't think the Windows Calendar app supports .ics import. I think the only way to do it is to import into calendar.live.com