Is it possible to set the duration of the cell to the length of the specific month?
First cell - April 2009 - 30 days
Second cell - May 2009 - 31 days.
Third cell - June 2009 - 30 days
Unfortunately, this is not possible out of the box.
You could however simulate it by showing 12 days, rewrite the header and translate days into months in the code behind. But this wouldn't be a general solution, it would work only for specific cases (if your events start and end with a month).