For the purpose of this Act the following terms have the meanings ascribed to them:
"Bill" means legislation drafted in the form of an act for introduction into either the House of Representatives or the Senate of the General Assembly.
"Opening day" means the day fixed by the Illinois Constitution for the convening of a regular session of the General Assembly.
"Filing period" means that period of time commencing November 30 next preceding opening day of the session for which the bill is filed under this Act and continuing up to but not including such opening day.
25 ILCS 25/2