Code/plugin/module to create PDF of website calendar [closed]

I’m trying to find a method to create beautiful PDFs of website calendars. An example of what I’m talking about can be viewed if you click the Create Brochure button on this website.

Note: You may need to click the calendar icon in the top right, then click the icon next to it again to get the button to appear in the left column.

I see that it’s API driven. Is there an option out there that is not proprietary?