Field help (DAYLTI_SQD) 

This is the necessary lead-time in number of days to deliver this ship-to customer. The lead-time is initialized by the lead-time entered in the quote header if the address on the line corresponds the address in the header. If it is not the same delivery address, the lead-time will be initialized to the lead-time of the entered delivery address. This lead-time will then be used to calculate the shipping date and the planned delivery date during the conversion of the quote into an order.

It the quote is about a prospect, the delivery lead-time will be systematically picked up from the header.