Marq~
In my opinion, the Waldorf Executive lounge will be closed. It was this year on Memorial Day anyway! However, I would think that as massive as the NY Hilton is, they would probably be open. Why not call the hotel direct and ask? Although that may not even help, as I called the Embassy Row Hilton in D.C. and asked if the executive level lounge would be open over the weekend (I had read in these posts that they didn't think the lounges were open on weekends) and they told me "No" when I phoned but when we got there the lounge was open. So, who knows....