Modeling A/R, Inventory and A/P

Hey guys, I know that when modeling working capital balances (accounts receivable, inventory and accounts payable), you usually calculate A/R days, etc. and then extrapolate using these drivers.

But if a company has both current and non-current A/R and inventories, do you add them together and then calculate A/R days and inventory days? Or do these days only apply to current A/R and current inventory balances (while keeping non-current A/R and inventory as a fixed % of sales and COGS)?

Thanks much!