The current month does not show Friday or Saturday. The Week, Month, and Year control icons appear at the top of the screen. Sometimes this seems to kick in when calendar events get rendered. That is, calendar shows current month correctly and then my events get displayed and the last two days of the week go off screen.
Rotated view shows these days. Other months display properly.
No messing about to get the current month to display properly anymore. Comes up correct and stays that way after holiday and reminder items have been pulled in.