Hello. I am currently in nyc.... want to visit this park tomorrow evening to get some long exposure night shots. However , I am seeing a show, which doesn’t finish till 930 . So won’t arrive till 1015. Does this place close ?

There are unobstructed views of the city from all along Blvd East even without having to walk into the park itself. There are no gates on the park so up until midnight you should be fine. Past midnight the police or security would ask you to leave

And even if you get locked out, you can take shots of NYC from nearby locations very easily.

The park has a sign that says it's open until midnight. So it probably is open until then.