My preferable monthly view is a calendar that shows:
(1) last week
(2) this week
(3) following weeks

A button to put it in this configuration would be great.

Agree. This is a must-have feature for me, and the only thing keeping me from switching to Proton Calendar.

In the Calendar app I am currently using, I can move seamlessly from one week/month to the next by scrolling. If in the month view, I can continuously scroll up or down (vertically). If in the week view, I can continuously scroll left or right (horizontally).

This is helpful, because if I have an event that spans weeks or months, I can easily see the entire event in one continuous scroll. I can start and stop a week/month on any day I choose, which will allow me to compare details from one event to a similar one in the next week - all without having to switch screens or copy/paste anything. And I can also move an event from one month to the next just by dragging. All of this has helped save me a lot of time when I have dozens of events to deal with per day.

Note: If I set my active Day/Week view to less than 24 hours (details below), then I can also scroll up/down in the week view to see the non-active hours. So in essence, the month view can continuously scroll vertically, but the week view can continuously scroll both horizontally and vertically depending on how it's set up.

If Proton can add this scrolling feature, I will definitely switch over in a heartbeat! Not just me and the others in this discussion, but I'm sure the rest of the users will appreciate this feature as well (I can see 2 other posts asking for the scrolling feature, which means there are others out there... just scattered).

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In addition to the scrolling feature - which I feel is indispensable for efficiency - there are a few other features that I hope Proton will consider adding down the line as well, because I feel that many users will find them quite useful. They are the ability to:

1. Set the number of hours shown in the Day/Week view.
This is helpful because if all 24 hours show in one screen, then each hourly-block will be very compacted. For me, I choose to show just my waking hours so that I can see more details for each event. Then if I want to see the non-active (sleeping) hours, all I have to do is scroll up or down on the screen. (Again, I can see 2 other posts asking for same thing, which means there are others out there... just scattered).

2. Set the number of days shown in the Week view.
This is helpful when you want/need your calendar to always show a certain number of days regardless if you're scrolling or not.

3. Option to show "Time to Leave", which is different from "notifications or alerts".
This is especially helpful in a group event. Because of it's name/label, people will know that it's not just a reminder to get ready, but rather a reminder that they actually have to get out the door by a certain time in order to get to the event/appointment in time.