Section 232 steel moved under an IT entry: which date sets the rate?

Non-quota merchandise that is subject to the Section 232 Presidential Proclamation regarding steel and covered by an entry for immediate transportation made at the port of original importation, if entered for consumption at the port designated by the consignee or his agent in such transportation entry without having been taken into custody by the port director for general order under 19 USC 1490, shall be subject to the duty rates in effect when _____.