ODDFYIELD stands for "Odd First Period Yield". It calculates the annual yield of a bond when the first period is shorter or longer than the standard schedule. In simple terms:If a bond doesn’t start on a "perfect" calendar (like paying every 6 months neatly), ODDFYIELD helps you figure out what your real return (yield) is. ✅ Regular bonds ➔ Use YIELD ✅ Bonds with odd first periods ➔ Use ODDFYIELD