I will gladly make the switch once a quality calendar feature is added AND an "undo send" function. :)

I agree with Ross: a searchable calendar would be perfect. Do you have a date to announce yet?

I promise to leave Gmail for good if you provide a calendar!!!!!!!!!!

I don't understand why Protonmail doesn't have an integrated calendar like other email services. Disappointing!

The day ProtonMail offers a Calendar is the day I leave Google for good.

Most other services are starting to offer this as part of a privacy package, this allows for an integrated calendar that would also be encrypted with the same protonmail magic!

Hopefully this includes full syncing with the address book of your phone/computer. It would be nice to have ProtonMail contacts available for use outside of ProtonMail.

share sheets would also solve this problem by sending items to the calendar (iCloud, or others)as well as to other apps like OmniFocus, EverNote, etc.

My calendar "asks" are:

1) Help me "push" selected personal Calendar Events from Protonmail into the CRM app for my cloud-based integrated business application suite (think Zoho One, Salesforce.com)

....BUT limit the information which which is pushed. For example, the pushed personal calendar event might say something like: “depart for 3pm appointment” and “estimated return from 3pm appointment.” To protect my privacy, it would not include the address, business name, or contact name.

2) Help me push an address stored in Protonmail into a driving direction application like Google Maps.

3) Help me avoid a scenario where I push encrypted [personal] Contact Notes from Protonmail into the Contact data I store in the CRM app for my cloud-based business application suite.

4) If a Business Contact becomes a personal contact as well, help me push Contact data to Protonmail from my integrated business application suite - Zoho One.

I realize that "Push" is a pretty vague term. It should not be interpreted to mean "automatically synchronize contact information between Protonmail and in my cloud-based business application suite-as-a-service if the contact is stored in both systems.

Would love to know if you think my "asks" are doable.

Please, please, please offer a SEARCHABLE calendar. I run a small business, and its absolutely imperative that we can search the calendar for previous meetings with specific clients or where the last meeting took place.
Search for encrypted calendars could be done the same as Tutanota do their search for encrypted emails: An index file is generated LOCALLY to enable search on the user's computer at that particular time. It works well. Similar to how password managers store everything encrypted in the crowd but still allow search on the computer when you are using them.

Pretty, pretty please with a cherry on top, please develop a search function for the calendar.

CALENDAR support and my last Exchange account will be transfered to protonmail. Mine and MANY of my customers', you would like it as much as I would!!

Please offer calendaring and a way to sync contacts to cell phone.

Notes, contacts, and a few binary files storage such as photos & sound-files.
(sharing the quota with e-mail is acceptable)
Managed by tags and list with simple search function.
And calendar.

Calendar is top request.

Document cloud would be great.

Notes would be nice but not essential.

Want to be away from google etc... calendar and reminders are a must

CALENDAR is the most important missing feature.

BTW, the Protonmail VPN May be Free, but you better have a good wireless plan, because when not near WiFi, it uses your Plan. Found that out, when it sucked by data away.

I like many others in this thread, wish to leave Google, totally. Will not move until Protonmail adds this feature.

I don't want to be tied to Gmail or Outlook any more.

Definitely a priority for me too.
As mentioned by many others, this is the feature that enables me to finally insulate myself from the usual service providers...