I recently worked on a computer with Office 2016 installed and the calendar was showing the dates in reverse order (as per image below). I checked all possible Windows and Office language settings and only English US was installed and configured/Enabled. However Outlook had the settings for Right to Left languages configured. If you experience a similar issue follow the steps below to change Calendar formatting back to normal.
- Open Outlook
- Click on the File Menu (top left) and Select Options.
- Select Advanced on the left hand side menu and scroll down to the Right to Left heading.
- Tick Arrange panes left to right for right to left languages and the two Left to Right radio buttons as per the image below and click Ok
- Restart Outlook and the calendar should now show dates in the correct order