Offline is a must. I also use a Business Calendar for android which is a superior calender app but I cannot sync it with proton. Only import.

The built-in app I used before was perfect; it was snappy (no web UIs), had Japanese localization, and most importantly, was not tied to my online status. The one big glaring downside was its coupling to google, which is why I switched to Proton for the time being.

Please implement offline mode asap; it's so annoying putting in an appointment, remembering you're not inside a local hotspot, and having to later remember to reopen the app, praying that the entry you made hasn't been dropped from RAM yet.

Hmm... Proton Calendar works for me while I'm offline. Maybe you want to report this is a bug?

I decided for the paid subscribtion to soon. Proton falls short on many aspects that other (free) mail and calender services allready have.
Please tell costumers in advance things like the impossiblity to use calender and mail offline. This should not have been offered in a payed subscription.

This is for me one of the main reason for not doing a full switch to Proton.
It's really a must-have feature for the mobile apps...

It would be great to be able to access read emails with the mobile app.
I have been already in situations, e.g. traveling to a different country, in which I was not able to access important information that I had in my protonmail account.

Do you think it would be feasible implementing this feature in the mobile app?

I can only agree. Not only is an offline view useful (i.e. think of mobile use, no Internet connection), it also allows to work on it, in case of a disconnect from anywhere. You simply sync the calendar with the server, when you go online with both versions.

Would really like the option to access some emails (if not all) on my iPad offline. This is critical for my continued use of this app.

Using the calendar offline is a big Must! I travel/work a lot in areas with almost no to no signal and without wifi access.

As anyone who frequently travels, being able to access and add/edit/delete entries while Offline for later syncing is a must have.
I would prefer this in your own dedicated app.
I can't use Proton for calendar purposes until this is fully implemented

I'm surprised that you can't even edit and save a calendar event without being online. Any old PWA can do offline then synch, let alone a proper Android and Apple native app. Craziness. This needs to be implemented asap.

I agree, I am a visionary subscriber and have moved all my Google/Outlook accounts to ProtonMail. The emails, contacts and calendar shared between my mobile phone, my Linux PCs and my servers are critical.

The ability to share my calendar (several of my accounts) in read (already possible) but especially in write with my applications is essential.

A shared calendar with a third person is also a big plus!

I think CalDav is essential to use the calendar on multiple devices. Please add the support, it is very important!

Same here. On Gmail (which I'm currently migrating away from, if I don't have network, or the network is slow, I'm still able to view emails, especially if i need to check emails for references or information I need). I'm unable to do this with Proton, sometimes even the folders don't load.

Agreed. I signed up for premium because I just assumed that like any modern system, Proton's calendar would have CalDav support. I'm going to switch when my renewal comes up. Not having the calendar available in the field and not being able to merge it with other calendars makes it useless.

Agree - if there is a bridge available on iOS to the native calendar app, this will be so helpful. I can also have the calendar notifications / visibility on Apple Watch.

I agree with this
I also refer to another suggestion that integrates this suggestion:
https://protonmail.uservoice.com/forums/945460-general-ideas/suggestions/36650287-all-in-one-proton-desktop-app

This should be available on all platforms (starting with Android and iOS since they already have apps). Sync back once the network returns.

This is one of the missing features that prevents me to go to paid plan

Adding my voice here too. Sometimes the network is down and I need to access a boarding pass in my emails.