I will not be renewing my subscription if this feature is not implemented by the time my current subscription is up; I have given Proton the benefit of the doubt when it comes to new features since 2018; with the release of Lumo, Wallet and Authenticator, I have lost faith that they value quality over quantity. Providing a way to integrate your calendar with other calendars such as a work calendar by way of an email application like Thunderbird is a mind-boggling decision to me and shows that the people in charge of the Proton product roadmap prioritize users with very different needs from me. That's obviously fine, it just means that I have to find a product that does meet my needs (or self-host).

This is the only thing that prevent me to start fully using proton !

Please add this.

Hugely essential

This is very important. Especially since you can only delete all your calendar entries in Proton. Thunderbird would allow ability to delete a date range.

Please add this functionality.

Lack of Proton Calendar in Thunderbird kind of demotivates me from using proton calendar at all, since I need each of my multiple email accounts and calendars accessible in Thunderbird, and being forced to use a separate web app just for Proton Calendar is bad UX. Having Proton Calendar as a part of Bridge is a necessity for me.

I think I understand the privacy trade-off, but for the calendar to actually be useful, it needs to be able to integrate into Thunderbird (me) or outlook (partner) like Gmail and others. Is there any timeframe?

Agree this is a major gap in integrating with Betterbird/Thunderbird. I have many email and calendar accounts. Moving to separate mail and calendar interfaces in Proton is not a useful option.

Agree with the comments. This feature is critical and is currently a key gap in the Proton offering - if this was in place it would allow me to complete my migration to fully embrace the ecosystem. Without this feature I'm forced to leave myself with one foot in the other camp...

THIS needs to be prioritized. Seriously a huge downfall to the Proton ecosystem. Not too many people out here are using Proton, so it makes it essentially useless for anyone to share a calendar, currently. I mean yes, for an individual it's fine, but for the majority of us who needs to share events with friends, family or coworkers it is extremely inconvenient.

I need mail, contacts, and calendar to be part of the bridge so that Betterbird/Thunderbird can access them each via 2-way sync. Having only mail is just a partial solution.

As a dedicated Proton user, I greatly value the privacy and security that Proton services offer. However, the inability to integrate Proton Calendar with native applications like Apple Calendar presents a significant limitation in my daily workflow.

I propose enhancing the Proton Bridge to support CalDAV, enabling seamless synchronization of Proton Calendar events with desktop calendar applications such as Apple Calendar and Thunderbird. This integration would allow users to view and manage their Proton Calendar alongside other calendars in their preferred native applications, improving usability and efficiency.

Currently, Proton Bridge facilitates synchronization for emails and contacts via IMAP/SMTP and CardDAV, respectively. Extending this functionality to include CalDAV for calendar synchronization would provide a more comprehensive solution for users seeking to consolidate their communications and scheduling within Proton’s secure ecosystem.

This feature has been a recurring request within the Proton community, as evidenced by discussions and suggestions on the UserVoice platform. Implementing CalDAV support through Proton Bridge would address these user needs and enhance the overall appeal of Proton services.

I kindly urge the Proton team to consider this enhancement, which would significantly improve the user experience for those who rely on native calendar applications in their daily routines.

I can share calendars from Proton Calendar to Thunderbird as read-only but I cannot add/amend events from Thunderbird to Proton. This is a nuisance since invites arrive in email via Thunderbird. Of course if I accept them then they are added to a local calendar, but then I can't see them in my Proton calendar.
My rather convoluted work around is to copy the event from my local Thunderbird calendar, then paste into a plain text file (using MacOS, I use TextEdit), and save with a .ics file name. I can then import this into my Proton calendar accessed with my browser. This is fine for a few events but a right nuisance for all of my calendars.

Very critical !

Has Proton even responded to this feature request?

Very critical

Please get this fixed - really not an option using Proton mail app on windows, as i do not support localization, so for me Thunderbird is the thing - but then again, no calendar !

How can this take so long ... ?

Please, please, please! A CalDAV/CardDAV bridge would make Proton such an easier sell to customers. I’ve already moved my contacts to a self-hosted solution and I really don’t feel like doing the same for my calendar seeing as I’m already paying for Proton Calendar. Please put this on the roadmap!