Date not changed on PO receipt header

We have created a receipt on back date.At the time of creation we give back date on receipt header and then save it.

After this we inspected the receipt and then deliver it to the destination..

All Transactions were performed on back date.

But when we find our receipt at Find receiving transaction window, it shows current date on header and at line level all transactions were performed on back date.

Kindly give me the solution that how receipt header date is automatically changes?

Thanks