Invoice custom due date should allow specifying in Net days (in addition to date)

I’d really like to be able to specify a custom X value for “Net X” terms of an Invoice’s Due Date.

I have a customer who requires Net 53 (yes that’s right, Net 53) payment terms. I’m finding this very difficult to handle in harvest, since I have to manually figure out the actual due date of the invoice.

The Invoice Due Date field is a drop-down list with the options: “Upon receipt”, “Net 15”, “Net 30”, “Net 45”, “Net 60”, and “Custom”. If I choose “Custom”, then a text box field appears when I can enter a date. If I click on the text box, a Calendar Control appears. That’s very nice, but if I try to type something like “Net 53”, I get an error from the input validator that says “this date does not seem to be valid” and it changes the value to “53” (which isn’t a valid date, obviously).

What I’d really like is to be able to specify a custom X value for “Net X”. I can think of a couple implementations:

Implementation A: the Due Date field’s input validator could allow me to type “Net 53” and then do the math and convert this to the correct date, 53 days from now.

Implementation B: there are two “Custom” options in the Due Date drop-down selector: (1) Custom Due Date and (2) Custom Net Days. If I choose #1, then I get the current behavior. If I choose #2, then I can enter the number of days (and maybe have some indicator display the actual due date).

Thanks for listening,