Calendar navigation
Go to calendar by clicking the "Calendar" button in left hand menu, or by pressing the following shortcut: G then C.

All navigation buttons are located at the top of the page.
Changing views
In the top right hand corner select the view you wish and click on it. The calendar grid will change accordingly.
Moving to previous/next month, week or day
Use the arrows in the top middle of the Calendar to move to recent dates in the past or future. Alternatively, you can also use the following shortcuts: press N for next or P for previous.
info_outline Note that it depends on the view you are in whether you jump to next/previous month, week or day.