IRR is simply the series of cash flows, along with an optional, estimated
IRR. If you don't put the estimated IRR, Excel uses .1 as its starting
point. Therefore, if your series of cash flows are cells A1:A5 and your
estimated IRR is in B1, then =IRR(A1:A5,B1) would be your formula.
The syntax for NPV is (discount rate, value1, value2,...valuen) If you are
using the same cells as above, it would be =NPV(B1,A1,A2,A3,A4,A5)
As for the time period represented by each cash flow--if you want to
consider each cash flow a period of one year or one day, that is your choice.
Dave
