Is it permissible for an employee to work one hour a day instead of eight hours, while still accomplishing the same amount of work previously required of him, especially if the manager refuses to increase his salary despite the improvement in his performance?

A private employee (Ajir Khas) is entitled to their wage by making themselves available for work, whether they actually perform it or not. They must complete the work on time without deliberate delay or deception. All of their time is dedicated to work, except for the times of prayer with their confirmed Sunnahs, and for eating, drinking, and relieving themselves. If the company does not appreciate their work, this does not justify them wasting time. They may agree with the company to work on a production basis. The initial contract must be adhered to unless the company agrees to change it or its term expires.