About 

• Zero hour is a unique creation of the Indian Parliament and, further, is accepted as a convention as it does not exist in parliamentary rule books. 
• The period immediately following the Question Hour has come to be popularly known as the ‘Zero Hour’. 
• Unlike the question hour, the zero hour is not mentioned in the Rules of Procedure. 
  • Thus it is an informal device available to the members of the Parliament to raise matters without any prior notice. 
• The zero hour starts immediately after the question hour and lasts until the agenda for the day (i.e., regular business of the House) is taken up. 
• It is an Indian innovation in the field of parliamentary procedures and has been in existence since 1962.