What date must be overcome in a 37 CFR 1.131(a) affidavit or declaration?

This page is an FAQ based on guidance from the Manual of Patent Examining Procedure. It is provided as guidance, with links to the ground truth sources. This is information only: it is not legal advice.

When filing an affidavit or declaration under 37 CFR 1.131(a), the date that must be overcome is the effective date of the reference being used in the rejection. The MPEP clearly states:

The date to be overcome under 37 CFR 1.131(a) is the effective date of the reference (i.e., the date on which the reference is available as prior art).

It’s important to note that for U.S. patents used as references, the date to be overcome is not the foreign priority date. The MPEP explains: The effective date of a domestic patent when used as a reference in a rejection under pre-AIA 35 U.S.C. 102(e) is not the foreign filing date to which the application for patent may have been entitled under 35 U.S.C. 119(a) during examination.