You have been warned, the recent 5.0 upgrade for Android app Google Calendar is a major revamp. It removes month view from phone, and also for week view and day view, you no longer can “zoom out” to see the overall availability. More on how the new version looks like, feel free to search about “Google Calendar 5.0 Android“.
But for me, I am downgrading my app to the previous version. The most recent pre-5.0 Google Calendar apk on apkmirror is 201404014, released on 02 Oct 2014. You can proceed to the following link for download. Do remember to uninstall the Google Calendar on your device before installing the downloaded apk.
Life is never better after this downgrade! Now wait for Google to revert its design flaw.