Google Calendar can't subscribe to icalendar feed over https?

I can confirm that (today) Google Calendar can successfully subscribe to an HTTPS iCal feed.

You can test this yourself by adding this URL: https://events.stanford.edu/byCategory/2/eventlist.ics

To be extra sure I also did another test of giving it an HTTPS url that didn't also work if you replace the https -> http. That was also fine, so in all cases, HTTPS should work.

What doesn't work in my tests is:

• HTTP Authentication (https://myusername:[email protected]/) - I got "Could not fetch URL" - but that's not what this question is asking.
• Any URL over 256 characters. However, using a link shortener (e.g., goo.gl) works around this issue.

Google has confirmed that it really is an issue with HTTPS, i.e. Google Calendar is unable to subscribe to iCalendar feeds from external encrypted (https) URLs.

My employer has an enterprise account with Google, and we filed a support request with google's enterprise support, with example feeds and our own assesment of the problem.

Today, we finally got a proper answer, confirming our initial analysis and informing us that the correct techincal team has been notified and an internal feature request (for supporting feed from https-urls) has been opened.

We were not given any timeframe for the fix, but I requested that they get back to us when the issue has been resolved. I will add that information to this answer once I receive it.