Your native calendar widget is ugly. Either provide more choices or allow us to sync with Google calendar seamlessly instead of having to export entries and manually sending it to Google calendar.

At event/appointment creation, one should be able to choose a color for it, independent from the current calendar color. All of these events and their colors would appear in the calendar and in all views.

I use multiple calendars in Office 365, each color coded to use, (personal, business, holidays, etc.) When on my desktop with the calendars overlapped I can tell what the appointment is by it's color.

I would like to see those same colors sync with the Outlook app on my Android phone.

calendar widget should show events from imported calendars (like Facebook event calendar)

When I use Windows Outlook Calendar I can assign Color Categories.
But in Android I can only see the colour with te Tag Category but not assign a category to a new event created from my phone.

show notifications from Google calendars in Outlook calendar application

Allow a calendar event to utilize more than one reminder. Certain events will want reminders at multiple times without having to edit the event every time. 1 week, 1 day, 12 hours, etc. for doctor's appointments and such is really helpful.

when I'm using the Android app I cannot simply copy a single event to another day. sometimes it happens that I want to copy a particular event and move this copy to another day for example I have a second meeting concerning the same matter. that would be very helpful if you could put these kind of possibility into the calendar app.

From open email, being able to "add to Calendar" and open new calendar entry dialog with the body, sender, date of email message in NOTES field.

Search in calendar for same events past and future.

Change the text in calendar month view to black instead of white so it is easier to read

enable swipe options for Outlook calendar, like with the mail

Make Calendar events show up on Android auto, this allows us to join meeting remotely when driving. Also manager schedule on weekday, as my work uses Outlook 365.

being able to see "other calendars" or shared calendars in outlook on Android for exchange accounts is a needed feature. the mobile owa has this feature, I'd like to use the app completely.

Single day widget, same as the single day view in the Outlook app's calendar.

In Outlook (on desktop) and several other calendar apps it is possible to color code appointments. In the Outlook app, unfortunately these colors are not shown. This is quite annoying as I color-code many of my appointments to distinguish between different types. (e.g. private vs work or returning meetings vs priority meetings)