Calculating patent expiries for most countries is relatively straightforward. Some countries even calculate it for you and display it in a field in their online databases. Why then, is it so difficult to accurately calculate expiry dates for US patents, and be confident in your answer?
This is a shortened version of a full article which can be accessed at Considerations, concerns and recommendations in calculating patent expiry dates for United States patents, and it’s been some eight years since this article was first written, so it’s natural there will have been some changes made in that time. We’ll look at those later, but first, let’s recap.
The commonly held view of how to calculate US patent expiry dates is as follows: Read more