I am looking to minimize app switching, I would love to see Proton Calendar have an option to sync from a Gmail one.
Implementing a native feature to redirect an external calendar events directly into the Proton Calendar UI would be interesting

Pull the calendar entries/meetings from Gmail, Outlook, Apple Calendar to Proton Calendar.

Not necessary for two-way sync, just a pull to one master calendar.

Thank you!

Like the others, I need two-way sync in order to be able to use Proton Calendar. It is not optional.
If only you could find a secure way of enabling two-way sync while keeping Proton's encryption.
Until you find a way, i'll have to use other calendar clients.

Keep up the good work!

Maintaining separate calendars is both inconvenient, but also doesn’t identify time or date conflicts. Syncing with shared calendars others include you on need to be accessible from one place. Marking them as not secure would be fine. I just can’t justify using separate calendars so will continue sticking with other Calendar Apps and only using Proton Calendar for things that need to be private. Information in multiple places is just not practical unless I keep duplicate things as dummy events in the non-Proton one to block out time slots and keep that updated manually.

This is so critical. A lot of my ecosystem is on Google Calendar, and right now Proton Calendar is an all or nothing approach. I need a gradual migration story.

I have the same situation as Arno.

Becoming increasingly necessary as I coordinate my external work calendar with my family. At this point, due to meeting changes throughout the week (or even day), it's literally easier for me to maintain two calendars (work + Proton clone) so my family can be aware and adjust necessary schedules, or that I could do the same as their own schedules update. We don't need details, but some level of being able to simply see an external calendar's event exists and label it as "Busy" is needed.

The issue I have is Proton Calendar customization and interface options are too limited for my productivity. I would rather use Proton Calendar but it takes me literally 2-3x the time do to anything due to either extra steps or additional work-arounds I need to accomplish due to the lack of features. This is the main reason why I would want read-write access from another app is so I can take advantage of other app features.

Maybe Proton can use a Proton-Bridge like feature for calendars like it does with mail?

+1

Honestly I would be happy with just a 1-way-sync (automatically adding new Google events to my Proton Calendar)

At the moment I manually use the import function (weekly), but that's certainly not ideal.

It is indeed very necessary! The other way around would be a great step forward: beign able to add/remove and see calendar events of 0365 and GMail from Proton would solve 80% of this issue without compromising anything.

I acknowledge the Proton privacy goal - especially for mail content. It is however critical for me that Proton provides an option to sync calendar and contacts to native device apps. It should be my choise to "expose" contact and calendar data to a non-encrypted application.

Being able to sync my work Outlook calendar with my private proton calendar is a must for me. I can set it up to sync and it pulls in the data, but it always becomes un-synced the day after and never gets any updates/changes to the calendar. This and a lack of todo list/task/notes functionality makes it unusable for me compared to google calendar at the moment.

Two way sync between apps, yes. Thunderbird integration with Proton Bridge would be a start.
CalDAV full support would go a long way in usability and adoption, as well as the ability to at least support credentialed iCal formats.
Additionally support for FREE/BUSY data information within calendar events is something else that is critically missing.

Frankly as it stands now, Proton Calendar is simply not enough except for casual use. Too many road-blocks and unsupported integrations stand in the way. If Proton Calendar interface and applications cannot support these things, then Proton Calendar MUST be supported READ/WRITE in many iterations and use-cases within OTHER apps that can and DO support all the necessary interoperability features between the different calendaring platforms. This at least would make scheduling within Proton Calendar as a back-end viable for work/life.
Again, as it stands now, this is just not possible except in the most multi-app and fragmented state.

Given the current political situation, I am very keen to move away from big US tech firms and onto the Proton platform. The lack of calendar integration (Google / Outlook/ Todoist) is currently a deal breaker for me however.

Please prioritize this update!

I've voted for a similar one earlier (someone linked it in the comments below). I need to be able to share my proton calendar with my husband's Google calendar.

Critical

I think this one is similar or identical to this one:

https://protonmail.uservoice.com/forums/932842-proton-calendar/suggestions/39383308-bridge-support-for-calendar-outlook-thunderbird

Real-time bridge between Proton Calendar and Google Calendar. I want personnal things added to my Proton Calendar automaticaly added to my work Google Calender with a "BUSY" or ""PERSONNAL" only label. That way, co-worker knows i'm not available, but don't know the exact reason.

2-way calendar sync please between proton bridge and Outlook.