Option 1: The time allotted after the Question Hour. This option correctly describes the zero hour. The zero hour is the time allocated after the Question Hour in the Parliament. During this time, members of the Parliament can raise important questions or issues of national importance or grievances of the people.

Option 2: Questions on issues of national importance or serious grievances of the people can be raised by members of either House. This option correctly describes the zero hour. Members of either House of the Parliament can raise questions or discuss important matters during the zero hour.

Option 3: Questions to be asked during zero hour are circulated one day in advance only. This option is not a correct description of the zero hour. Questions during the zero hour are not circulated one day in advance. Members can raise questions or issues spontaneously during this time without prior notice.

Option 4: The justification for its origin lies in allowing for democratic discussion beyond rules and procedures. This option correctly describes the zero hour. The zero hour provides an opportunity for democratic discussion beyond the rules and procedures of the Parliament.

Therefore, the correct answer is option 3.