The behavior of this hint has changed slightly with Mavericks Calendar app from the older iCal method.
Now you first need to go to day view (e.g., by pressing Command+1) and then you can use Command+Option+(2-6) to view 2 to 6 days in the week view.
It would be nice if something like this was also available for month view (2-4 weeks) and year view (2-11 months).
[crarko adds: Not much for me to add here.]
Source: Mac OSX Hints