I don't think FANDOM Business Hours ever end. It is a worldwide thing so there is always people online, and the site never goes down, A new day starts at 8 PM EDT or 7 PM EDT from November through March.
To be honest, I would have thought it would be PT since that is where Fandom's HQ is. However, that clearly isn't the case since, even if we assumed as late as 6 PM ET, that would only be 3 PM PT. Splitting the difference between the times I found, I guess CT makes sense. But the only reason I couldn't get more specific than that 2 hours window is because I just don't have any tickets submitted within that window. At least, not from the past 6 months.