My husband and I have 2 layovers at JFK, arriving @ 9pm and leaving next day @ 8 am on April 1 and April 9. Would like to have dinner, go to Empire State bldg, enjoy a club. Suggestions? Will be taking taxi from airport. Thanks

First of all, I assume you bags will be checked through to your final destination.
I believe the Empire State Building closes at 11 p.m., so you may not have that much time to get to the top.
As for dinner, the earliest you can get to the city will be 10-10:30. So, by the time you finish dinner, you're talking about 12-12:30 at the earliest. Of course, that's all assuming your plane arrives on time!
What kind of a club are you talking abou? And, do you really want that much activity knowing you'll have to be back at the airport by 6:30 a.m. at the latest?

Arrival time at 9pm probably means you won't be off the plane until 9:30. You won't be in the city before 10:30 and possibly later. Dinner options will be limited and that might be too late to visit the Empire State building. And then there is the cost - a taxi to the city and back is going to cost a minimum at least $85

Thanks for being so helpful. Our luggage will be booked through so that won't be a problem. Actually, we were just looking for something to do rather than be at the airport from 8 pm to 6 am the next morning! Any suggestions will be appreciated!

Maybe you should explore some of the well known neighborhoods in Queens near JFK.
There is Howard Beach - home to the Gotti family,
The Rockaways - think of The Ramones, Flamingo Kid, the plane that crashed in Bel Harbor days after 9/11,
Flushing - NYC's current Koreatown and Chinatown,
Jamaica - hometown for many many Rap and Hip Hop artists,
There are also Aqueduct and Belmont Racetracks and the West Side Tennis Club and Flushing Meadows (the US Open).

So unless you must go into Manhattan, enjoy Queens.

If you want to stay in Queens, you might want to opt for Austin Street in the Forest Hills area, which has a lot of fine restaurants and a latin nightclub in the area.

If you have your heart set on Manhattan, there will be places open late, however your choices will be a little more limited than normal at that hour. All the nightclubs don't start to get crowded until midnight, so expect lines even at 11:00.

Just to add on....

McSmith, not to say your suggestions aren't good, but let's get realistic. Their layover is overnight. Would you really want to send tourists who are not familiar with NYC into Jamaica, Queens late at night? Not the best idea considering it's not the safest area. Ditto on the Rockaways. (I live right over the bridge to the Rockaways in Brooklyn, so I know.)

Also considering their time frame, the racetracks, tennis club and most of Flushing Meadows would be closed.

OK, my mistake, I thought they were leaving the next day at 8pm. All my suggestions were for daytime.