MPEP § 2754.01
An application for patent term extension under 35 U.S.C. 156(d)(1) may only be filed within the sixty-day period beginning on the date the product received permission under the provision of law under which the applicable regulatory review period occurred for commercial marketing or use. The statutory time period is not extendable and cannot be waived or excused. See U.S. Patent No. 4,486,425 (application for patent term extension filed after the end of the 60-day period and was therefore denied). For purposes of determining the date the product received permission under the provision of law under which the applicable regulatory review period occurred for commercial marketing or use, if such permission is transmitted after 4:30 P.M., Eastern Time, on a business day, or is transmitted on a day that is not a business day, the product shall be deemed to have received such permission on the next business day. The term "business day" in this context means any Monday, Tuesday, Wednesday, Thursday, or Friday, excluding any legal holiday under 5 U.S.C. 6103.
For drug products the approval date is the date of a letter by the Food and Drug Administration indicating that the application has been approved, even if the letter requires further action before the drug can be marketed. Mead Johnson Pharmaceutical Group v. Bowen, 838 F2d 1332, 1336; 6 USPQ2d 1565, 1568 (D.C. Cir. 1988). For food or color additives, the relevant date is the effective date of the regulation or order, which is set forth in the regulation or order, and generally is the date that the regulation or order is published, e.g., in the Federal Register. See 21 U.S.C. 348(e). This date will generally be later than the date the approval is communicated to the marketing applicant. However, in the case of drug products for which the Secretary of Health and Human Services intends to recommend controls under the Controlled Substances Act, the time period is as described below.
Where the regulatory review is of a drug product for which the Secretary of Health and Human Services intends to recommend controls under the Controlled Substances Act, the sixty day period of 35 U.S.C. 156(d)(1) begins on the "covered date," where the "covered date" is the later of: