Estimation amount by selecting Date

Hello,   Currently am working on project (Library Management) i faced one show stopper as i have 'Customer' as a user role , here i gave books in list view when customer logs in he can borrow the book i have given discount functionality  (Admin will give). i took two attributes like one will show amount like 'Book Price ' another one is 'Rent' per book. Customer will be navigated to Details page when he choose rent option and here he  should select date like 'Return Date' from 'Current date' . i want the Estimated amount when customer choose  for 5 days - one  amount, when choose for 5-10days - another amount period wise it should display. Like this i need an estimated amount when customer selects the Return Date per book . can i take extra attributes to achieve this or using text widget can we show data. which one to use. is anyone tried this before suggest me how to do.     Thanks in advance Pavan  
1 answers

You could create an on change microflow and set it on your 'returndate' attribute in the page. If the user changes the return date, this microflow is triggered. In this microflow you can calculate the 'estimatedamount' attribute.