MusicRadioUSA, obviously you didn't click on the link as JoeyBagODonuts suggested. You would then been directed to the website for Nassau Financial Federal Credit Union which contains the same "75th Anniversary message" and logo: celebrating the 75th Anniversary Of Nassau Financial, not WHLI. Also, the "75th Anniversary message" on the WHLI website is only contained within the "advertising box" for Nassau Financial and not anywhere else.
I'd suppose that WHLI would have a significant anniversary displayed prominently on their website with links to further info. I'll admit that the 1st impression that the ad's placement and layout gives is that it's related to WHLI in some form or fashion...until you read further down and see that it's related to Nassau Financial. Also clicking on the message/ad would have revealed the ultimate answer.
Besides, as Joey mentioned (and can be easily found via internet search), the station signed on nearly 64 years ago on July 22, 1947.
Link:
http://en.wikipedia.org/wiki/WHLI (Granted, the accuracy of Wikipedia can sometimes be shaky.)
Side note: while not totally out of place here on the New York, NY forum, there is a Nassau-Suffolk (Long Island) forum located within these message boards where this post/thread would probably have been more appropriate.
Sorry for the "lecture" nature of this post, just that the internet is your friend - use it to your advantage to research and discover if you're unsure of something.