Basis is a multiplier used to calculate the total interest paid or received in a defined time period. It is typically used in accounting and valuation for bonds, swaps, dividends, project finance, and other investments with periodic cash flows. Basis is also known as the "day count convention" because it defines how days in a year are treated for calculation purposes in different parts of the world.

Discounted 360
Discounted based on actual number of days in the interest period divided by 360. For a principal of P, a discount rate of R, and a period of d days, the interest calculation is P x (d/360) x R x (1- R/100).