This is where you enter the actual operation time for the quantity that you are reporting. The planned operation time is suggested if you have checked the Suggest rest on operation and Time options.
If it concerns a subcontract you do not enter a time here, instead you enter the actual subcontracting cost in the currency that is registered on the operation.
When reporting subcontracts, you can create a supplier invoice basis. This is determined by the setting Create supplier invoice basis during subcontract reporting? under Accounts Payable under the Purchase tab in the Settings procedure. In this case, this field will show zero and is greyed out and no subcontracting cost is entered here, but this takes place when the invoice is registered in the Register Supplier Invoice procedure.