TBILLPRICE function returns the price per $100 value for a treasury bill where @settlement is the settlement date and @maturity is the maturity date of the bill. @discount is the treasury bill's discount rate.
If @settlement is after @maturity or the @maturity is set to over one year later than the @settlement, TBILLPRICE returns NUM! error. If @discount is negative, TBILLPRICE returns NUM! error.