What time in the day do you stop a KDP free giveaway?

I'm sure the deadline's probably passed by now, but other people might be interested in the discussion. Personally, I think with there being so many different timezones involved, finishing times don't really matter.

When you make a book free on Amazon.com, is it also free on .co.uk, .fr etc?

Can you end a giveaway early? I wasn't aware that you could.

What you get from the free downloads is a chance of reviews, relevant books in the 'also bought' section, and possibly sales of your other books (if you have any... good for the start of a series, for example). Which will hopefully net you a few paid sales. Ranking is not a big thing with the free days anymore, as they changed the ranking algorithms so free downloads don't count for very much.

I don't see any advantage in cutting off a promotion early.