How to make a Pocket Calendar Booklet with two page spread without cropping?

How do I effectively split a page at the center so the left side is the top of the calendar and the right side is the bottom?

I have used datamerge to make the months, then when I put the adobe acrobat print setting to booklet, there isn't a way to split the pages in the center.

My first option is to just crop the pages and then manually do that for 24 pages, but is there a better way? For instance if you are making a magazine and you want oversized pages to tile (i.e. picture spreads) would you have to manually do that, or is there a way to do that Indesign better than the crop version?

If you want to see a picture of the process I did let me know if it will improve your answer.