Weds night were usually student nights when I was at uni so although it's a couple of miles from York Uni the pub was right by students living in that area so I assume they'd have put something on to attract more.
Pub quizs could happen any night although usually a Sunday where I live and given she belted out Elton John painfully on a regular basis I assume they did karaoke nights.
@moonsafari would confirm anyway if she hasn't already previously.
I assume given she was comfortably inviting her dad to the NH on a regular basis she also invited some of her work colleagues there on occasions if they didn't live too far so that must be another angle the police looked at some stage.