This sounds like a general request to give more information in Outlook calendar view.

can someone test this and see if outlook now does this? I think it might. cc @josephsl

I can verify this in Outlook 2016 (version 16.0.8201.2102). I can also verify in Outlook 2013. Quickly tested on a colleague's laptop. All relevant updates are installed.

Sometimes the nvda reads the appointments when walking with the arrows, the right and the left however for many times it fails and to see the appointments it is necessary to press tabe.

I think this could have negative effects on performance of NVDA while navigating through the calendar. NVDA is quite slugish when the calendar is quite full. Try to implement the holydays addin in ms outlook and you will see what I mean. I would rather recommend to change the view to active or list. You will then see all your appointments in a list. The appointments are sorted chronologically. In active view, the first apointment is the nex outstanding. In the list view, the first appointment is the very first which you have created or where you have been invited in ms outlook. it could be five years ago. You can sort your appointments by date, type and so on.

Respectfully I would like to disagree, other screen readers report the appointments with the right and left arrows on the calendar and there is no slowness.
I did tests in outlook 2016 and managed to get nvda to inform the appointments correctly, and with agility.
This makes my previous comment no longer valid.
I have not tested on other outlook and windows verifications.

It seems like this issue can be closed.