Using Dual view
You can display two calendar views at the same time. From Day,
Week, and Agenda calendar view, drag the calendar handle 
(at the top of the screen) downward
to display the Month calendar view above your existing calendar view.
Drag it back up to close it.
NOTE
When you select the Month calendar view from the drop-down menu (at the top left of the screen), it automatically displays the Dual view calendar. Tap one of the calendar tabs (Day, Week, or Agenda) to change the bottom calendar view.