How/who can mark it as done?

It is now possible to subscribe to ICS urls.

Yes. This would make it possible to access my Proton calendar from android's native calendar app (as well as others).

The existing calendar sharing option in Proton ought to be renamed to "export," since that's what it really does - export an ics file, which is pretty much useless as a sharing tool.

Absolutely yes! This is essential to enable adoption as a business tool. Otherwise you need to export your encrypted events to another insecure calendar in order to see your schedule in one place. Much better to import the insecure / externally scheduled events to your private and "secure" schedule.

I love this feature request.
It's currently labelled "ProtonMail", however it should be labelled "Proton Calendar"

This is really the same proposal as here: https://protonmail.uservoice.com/forums/284483-protonmail/suggestions/41975749-calendar-subscriptions#comments

I keep trying to get family members to use proton calendar but they say it is too hard because right now their work uses google calendar and they cannot see their work stuff here. If you allowed viewing of other calendar feeds within the proton interface, it would greatly increase adoption by users who have reservations about switching their current calendar.

This would be an amazing feature, and would greatly help users like myself while transitioning from other calendars like Google Calendar.

Specifically for me it would be great to have support for adding webcal feeds!

Would really like to add a calendar Feed option. For example, my children's school calendar has a Feed Link I can copy, but I can't download the calendar .ics file.

It's a MUST HAVE ...

Of course I understand that it wouldn't be encrypted, but I need to see multiple calendars at once: My personal one(s) (which I want encrypted), shared ones (with other ProtonMail users, encrypted), and also external calendars, like my company's google calendars (possibly using the ical secret link, or some other mechanism).

I desperately need this if I am to adopt ProtonCalendar as my go-to calendar. My university allows us to subscribe to our individual calendars via a URL link. If Proton is going to be a viable replacement for google services we need to be able to subscribe to URL Calendars.

This would be good.

For outlook, you can share free/busy status or more with a webcal://outlook.office365.com/owa/calendar/TOKEN link, after sharing. This would be very helpful to consolidate all calendars in one place.

Yes, absolute. I would need that too, to share with my to-do list app.

This is must. I cannot collaborate with my team if I cannot see their calendars.

This would be fantastic.

Yes, this very much! I'm using this option for several online calendars and this would be very handy.

This is a MUST. I need it for syncing showings for my house.

is there any update on this feature request?