You can look up the "Shipment Date" of your inventory by logging into https://mysupport.netapp.com. Then going to "Systems" > "My Systems". Then search as required.
There is a "Inventory" section where you can then view the individual details of each system such as shipment date, entitlement information etc.
Additionally, at https://mysupport.netapp.com you can look up all the Sales Orders that your company has had with NetApp and look up order date, shipment date etc per Sales Order.
Alternatively, you could also goto https://activeiq.netapp.com then click the "View All Sytems" button near the Inventory widget. It should show a nice table of all systems you can see from your account, their S/N, Shipment Date, Support Entitlement End Dates, and some other details.
If this isn't the information you are looking for, then I would suggest you reach out to your local South Korea NetApp Partner or NetApp Sales Team to help you gather the details you are looking for.
Hope this helps.