The Outlook calendar is really good and has widgets you can use - unless you have another account that must only use the Android calendar.
It was a while ago now that I used Outlook bit if I recall my bugbear was that it was a two step process to get to the calendar, having to open Outlook first rather than being able to go directly to the calendar from an icon. Also no doubt Outlook has improved since then.
That's why I use OneCalendar. . One icon and it opens and syncs up the Outlook calendar and Gmail if you want it.