I'm not sure if this behaviour changed during some recent update, but I'm pretty sure I would have noticed it earlier if it wasn't the case:
I have placed the "Calendar" icon on my Android home screen because it is the EPIM module I mostly use on my smartphone. When I click on it, the calendar always starts in the "Day" view, no matter which view was active when I closed the app the last time. It's 100% reproducible here:
- Start EPIM calendar from the icon
- Change the view to a different one (my preference is "Month")
- Leave the app (= go back to the home screen
- Reopen EPIM calendar from the icon
If I start EPIM from the launcher and choose "Calendar" from there, the last shown view is reused. Because the app behaves differently in the aforementioned cases I'd consider this more a bug than a feature.
(EPIM for Android 5.7.2 on Android 5.1)