Changes in wordpress script

I have a wordpress request modification the time not work well. I don`t know if is in theme or in plugin Exemple : If I select 2 days and 3 hours know say only 2 days price, need to show 3 days if have more that 48 hours like 49 and totla price to be show for 3 days And there is options to calculate price to dates if I select 3 days and a helmet cost is is 15$ to and select for 3 days, total cost to be 45$ I attached some files to undestand better Say the word "Chase" when you speak with me on PM to see you read the project No milestone provides I will pay when the project is complete