In previous versions of OS X, you could access a secret Debug menu in iCal - now Calendar - offering many interesting options. Apple removed any way to activate this menu in Mountain Lion, but you can still access some options. I like to have two weeks displayed in week view in Calendar. To do so, quit Calendar and open Terminal, then type:
defaults write com.apple.iCal CalUIDebugDefaultDaysInWeekView XXreplacing XX with the number of days in the week. You can even use very large values, such as 90, to display 3 months in a week view, though each day will be very small.
defaults write com.apple.iCal CalUIDebugDefaultDaysInWeekView 7and relaunch Calendar.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20120731054636997