Sorry for the long delay in response, been busy. I agree, there “probably” is no disadvantage, from a logical standpoint… However, I would be cautious. Usually if something is not standardized browsers tend to implement such things with little consistency, and sometimes without thought to possible issues. As such, my fear would be that a specific browser may not actually recognize an expires that far into the future (perhaps the programmer thought 5 years would be the most anyone would use), and instead would default to a smaller time or not may not function at all. Purely conjecture, but something to think about.