Twitterment and emotional geography

Another interesting tool to track Twitter conversations: Twitterment (beta version)

It seems that we speak (or/and feel?) happyer during the morning and the light hours
while we tend to be sadder in the night hours
Does that make sense? (Every time I read data I'm always afraid to forget something really important!)
However, it could be interseting to have the same statistics ordered by countries: and set up an emotional geography!
A new exciting promise for the tourism industry!

Any doubt about the week end?