My experience. Hope it helps.
My appointment at 24 Commerce Street, Newark was at 9:00 AM. I went there at 8:00 AM (there was a small queue). Once we got in, the guy at the gate said we are early and told us to wait in the lobby. At around 8:20 he allowed us in after checking the appointment letter. He also gave us a simple form for us to fill in. Once you fill in you go into another line for finger printing only. This line was again short. Here we have to show the appointment notice, completed form, and ID. At this point you will be given a token. When your number is called you will have to go in and get fingerprinted. I was out of the building by 9:00 AM.
My appointment at 24 Commerce Street, Newark was at 9:00 AM. I went there at 8:00 AM (there was a small queue). Once we got in, the guy at the gate said we are early and told us to wait in the lobby. At around 8:20 he allowed us in after checking the appointment letter. He also gave us a simple form for us to fill in. Once you fill in you go into another line for finger printing only. This line was again short. Here we have to show the appointment notice, completed form, and ID. At this point you will be given a token. When your number is called you will have to go in and get fingerprinted. I was out of the building by 9:00 AM.