"Opening Day is the beginning of a new Major League Baseball season. It falls around the beginning of April, signaling such a generational feeling of rebirth for some that the writer Thomas Boswell once penned a book titled, Why Time Begins On Opening Day.
Opening Day is a state of mind as well, with countless baseball fans known to recognize this unofficial holiday as a good reason to call in sick at work or be truant from school (as most teams typically play their home opener in the afternoon) and go out to the ballpark for the first of 162 regular season games.
Opening Day extends throughout the sport of baseball, to hundreds of minor league baseball franchises as well as to college, high school, youth league fields and in areas far beyond North America." - Wikipedia