Thunder Bay's downtown casino has really helped revitalize a formerly decrepit part of the city into the "Entertainment District", but it does draw a bit of an unsavoury crowd. I spent some time in its lobby on the Saturday before Hallowe'en and it was pretty intense what was going on at the time. Too explicit for this place.
It runs all day and night, with a few exceptions Sunday to Wednesday early mornings when they close it for a couple hours to clean up. So, like, if you want to go gambling at 9am on Wednesday or 5 in the morning on Sunday you can do that.

They have to stop serving alcohol at 2am though. I am not sure when they restart selling it; 6am I think.