Sunbird: Printing on 11x17 paper

I am trying to get my calendar to print on 11x17 paper. It will print on the paper, but it does not use the entire sheet to do so.

If I print it out in portrait mode, it only uses the upper part of the sheet. It is about the size that a 8.5x11 sheet would look if it were in landscape mode.

If I print in landscape mode, it will fill the page from left to right, but there is still about 4 inches of empty space on the bottom.

How can I get the calendar to fill out the page to all margins, or can I?