They have started, and there is more than one day. it's a whole week. Standard HHN has at least 3 rehearsals. Not even including the first night of filling out paperwork. The process is actually pretty annoying. Usually for rehearsals, you try a costume on the first night, you get instruction from show directors, formulate your characters. Second night you actually get to walk through what your area will be and such. Third night is when the executives review your project or area. This is going off of HHN. Kong could take wayyy longer than that. It's also not as easy as it looks to scare someone all night. It's more than just "popping out of a boohole."