Update Freight Order - Departure Date

Hi

I have  a requirement to update the existing freight order with a new Departure and Arrival date under Source group under General Data. I could not locate the fields in the structure of ITEM_TR node element of BO /SCTMS/TOR. The closest I could get is the STOP node element (/SCMTMS/S_TOR_STOP structure)  that has the field PLAN_TRANS_TIME. Is this the one I have to update. Or Am I looking at the wrong BO? We are in 9.1

Thanks ,Raj