Let's all hope that the mutant weekend plan is shelved before any other country gets that bright idea.
On the other hand, Chinese New Year gets more global attention than Cinco de Mayo. If we equate global acknowledgement of holidays with this scale, that puts China into the Superpower category and puts Mexico into the great power category (along with Ireland for St Patrick's Day).
On the other hand, if we're looking at items beyond the UK's failure to spread the festivities of Guy Fawkes Day, there are some other ways to measure a nation's power and influence.
Economically, I'd say the US, China, and EU all qualify as superpowers. In terms of foreign aid, China has been doing more and more in Africa. This, combined with heavy investments and trade deals shows that China is expanding it's influence beyond SE Asia.
Then there's the military. China trimmed its total number of military personnel, but the modernization pushes the country into the the great power category with Superpower easily achievable in the not too distant future. Watch how fast they expand their blue water navy.