A priority date is the earliest date on which an inventor can establish a date of invention. The inventor with the earlier priority date is awarded the patent.A priority date patent establishes the priority date as the earliest date an application may claim precedence. An application for patent filed in the United States may be entitled to the benefit of the filing date of a prior application filed in a foreign country. A claim of priority allows a later filed patent application to have a priority date as of the filing date of an earlier filed 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. BASICS: A "priority application" must "support" the claim with enablement and written description, but not with Sec. The nonprovisional application can claim priority to the earliest provisional application in the preceding six months. Use the USPTO's seven-step strategy for searching US patents to locate and evaluate relevant prior art (earlier patents and published patent applications). The priority date is the date you filed the first application.