So, you want to know, for business or cultural reasons, what holidays are celebrated in various countries? Here are some suggestions:
Time and Date lets you choose a date until 2015 and choose the country.
CountryReports is also useful. Though you need to scroll through the months to see the holidays, you can choose a country or region.
My favorite may be Earth Calendar, a "daybook of holidays and celebrations around the world. For the purpose of this web site a 'holiday' is any day that recognizes a cultural event, and not necessarily a day when businesses are closed.
Madonna - Holiday
The Bee Gees- Holiday