Celebrate good times! Celebrate!
You gotta' cut loose. Footloose.
You gotta' fight for your right to party!
Ok, I admit it. I'm a chid of the 80s.
All I'm trying to say is there are so many reasons to celebrate! I like finding new "holidays" to incorporate into our educational day.
It helps to plan a few days in advance if you want to include some books. Besides just reading, how about trying out different types of oatmeal and graphing which one is preferred during National Oatmeal month? Definitely need to play with play-dough on National Play-Dough Day. I think research skills should be practiced on National Bouillabaisse Day because what exactly is bouillabaisse?
To find out about all kinds of American holidays that you never even knew existed visit American Holidays.
Enchanted Learning Monthly Activity Calendar has both national and international things to celebrate along with links to activities for many of them.
Looking for holidays of specific countries? Try Wikipeida's list of holidays by country.
Don't neglect using celebrations for fun educational ways of integrating as many subjects as you like!