Step 1: Understand the relevant law.
The working conditions in factories in India, including the rules for child workers, are governed by The Factories Act, 1948.
Step 2: Know the definitions under the Act.
The Act defines a "child" as a person who has not completed their fifteenth year of age.
Step 3: Identify the specific provision for working hours.
Section 71 of the Factories Act lays down the rules for the working hours of children. It explicitly states that a child shall not be employed or permitted to work in any factory:
(Q) for more than four and a half hours in any day.
(R) during the night (between 10 PM and 6 AM).
This limit is set to protect the health, safety, and well-being of child workers.