Law passed today cannot apply to Past Events

In the case of CIT, New Delhi Vs Vatika Township Private Ltd and Others, the Supreme Court has held that law passed today cannot apply to events of the past. The court said that if we do something today, we do it keeping in view the law of today and in force and not tomorrow's backward adjustment of it. Every human being is entitled to arrange his affairs by relying on the existing law and should not find that his plans have been retrospectively upset. Supreme Court observed that the rule against retrospective operation is a fundamental rule of law that no statute shall be construed to have a retrospective operation unless such a construction appears very clearly in the terms of the Act, and arises necessarily by distinct implication.