What is special about April first?

April Fools' Day is celebrated in the Western world on April 1st of every year. Sometimes referred to as All Fools' Day, April 1st is not a legal holiday, but is widely recognized and celebrated as a day which not only tolerates, but encourages practical jokes. The day is special because it is a fun day when everyone must be "on their toes," so as not to be April fooled. Of course, getting through the whole day without getting fooled at least once is not an easy feat.