PPR 'Pay Through Date' vs. 'Additional Pay Thru Days' on PPR Template

Hi - we have a question regarding the logic behind PPR when used with a template. On the PPR job, there's a field named 'Pay Through Date' and on the template we use, there's a field named 'Additional Pay Through Days'. Currently, 'Additional Pay Through Days' on the template is set for 2 days. Does one of the fields override the other in any way? Can someone explain how these two fields do/don't work together?

Our process: Thursday's EFT PPR is dated thru Sunday using Sunday's date. So, in effect, we're requesting invoices due Thursday - Sunday to be processed for payment thinking that 'Additional Pay Through Days' on the template is overridden by the date on the PPR job. On Friday's PPR run, we use Monday's date in the 'Pay Through Date' field on the PPR request so we're looking for anything with a due day of Friday thru Monday.