A priority date is the date used to determine which of two opposing parties in a trademark dispute should prevail. Generally speaking, the one with the earliest priority date wins. The United States is one of few countries in the world that deems the date a mark was first used to be the priority date. Most other countries set the priority date as the date a mark was first registered. One exception to the U.S. system of setting priority dates is for the Intent to Use application, in which the priority date is becomes the date the application was filed rather than the date the mark is first used.
