What is the effective date for establishing common ownership under AIA 35 U.S.C. 102(b)(2)(C)?

The effective date for establishing common ownership under AIA 35 U.S.C. 102(b)(2)(C) is tied to the effective filing date of the claimed invention that is being compared with a prior application. This provision indicates that if two applications are commonly owned, the disclosure in a prior application can be used to negate any novelty issues regarding the later application. The term "effective filing date" refers to the filing date of the application that claims the benefit of the earlier application, providing a legal basis for assessing whether the same entity owns both inventions at the time pertinent for determining patentability. This allows for broader patent protection by ensuring that common ownership can negate potential prior art issues between related inventions.

The other options do not accurately reflect the AIA provisions. The date of the patent grant is relevant for determining the enforceability of a patent rather than establishing ownership. The date of first publication reflects when the earlier application was made publicly available, but it doesn’t define common ownership. Additionally, the date when a common ownership agreement is signed does not correlate with the determination guidelines of the AIA; it is the filing date that is the critical factor in establishing the relationship between the two applications for patentability assessment.