All who have PPO System v3.x spreadsheets! I have just discovered that the NASI values on the "Program" sheet are off by one day. To correct this error, replace the values with references to the corresponding NASI values on the "NASI" sheet. The current returns now with the corrected NASI values and some other tweaks are below: <img src=http://img119.imageshack.us/img119/1350/systemv407yo.png>