Open pdf document

Normally I open a pdf document directly from a link but suppose I want to add conditionality so that eg the pdf would open before 12.00 but not after 12.00. In that case I would like the link to go to a controller function where I could add the conditionality and then, if the condition is met, open the pdf. If I want to load a view I would use the load->view syntax but how would I load a pdf which is not in the view folder?

something like:

PHP Code:

function pdf_launch() {
 $this->load->view('public/pdf/test.pdf');
 } 


but that of course won't work.