A priority date patent establishes the priority date as the earliest date an application may claim precedence. The priority date is the date you filed the first application.Filed application for patent filed in the United States may claim the benefit of, or priority to, a prior application filed in the United States. A design patent has a maximum life of 15 years after the date of application. The date you first file a patent application for your invention establishes what is known as a "priority date". Patent filings based on US provisional patent applications. (in months from priority date) (status on 7 January 2025).