I believe claims last only until the next day, rather than 24 hours. Here is a quote from the rules:
"You can make 1 country per day (this may change to 1 per page, but for now, it is 1 per day), unless they are super tiny countries, in which case, 2 or 3 is fine (by super tiny, I mean Luxembourg sized!). You can use the rest of the day to fill in the history of the country. By 1 per day, it does not mean you have to wait 24 hours to post a new country, it means you have to wait until the next day. So you could post one at 11PM on one day, then wait one hour and post another one for the next day."
This, if we're going by the same definition of next day, also seems to make it somewhat clear when it comes to claims:
"You make a claim, then, before the day is done, you make your country."
I'll let you take Canada, but I would like for there to be a clarification so that, in the future, the rules may be followed more effectively.
EDIT:
With that in mind, I'll claim the Peloponnese.