Hi Vinod,
You can Chek in VOV8 T code There select The Order Type You are using In The Order under Requested Delivery date/Pricing Date There is a field Lead time in Days By default it is 7 days You can Make it 0. By default system Will take 7 days If you Make it As emty It Will take The 5 days from Material Master.
Thanks&Regards,
K.Mahesh Kumar