A watershed moment in the history was witnessed when judiciary of India criminalized the practice of Talaq-ul-biddat (instant triple Talaq) where a husband had a right to end a marital relation by pronouncing Talaq 3 times at one instance. This way of divorcing was held to be unconstitutional and majorly violative of article 14 of the Indian constitution.

In a renowned case of Shayara bano vs union of India and ors. AIR 2017 SC 4609 with Majority opinion of justice Rohinton Nariman J. and U.U. Lalit J. and a Concurring opinion of Kurian Joseph J. and a Dissenting opinion of CJI J.S. Khehar and Abdul Nazeer J. It was held that any man who pronounces instant triple Talaq would be punished with an imprisonment of three years and fine. The question is that whether or not the judgement pronounced shall be applicable retrospectively or prospectively, the same has been discussed below relying on the landmark judgements.

Judicial activism has played a vital role in the development of justice system of India. similarly, in the case of Shayara bano vs Union of India and ors. AIR 2017 SC 4609 judiciary while perceiving the situations of the Muslim women and an Unislamic practice of Talaq-ul-Biddat condemned such practice and furthermore penalized any such practice.

The court had held that instant triple Talaq given by a Muslim man �capriciously and whimsically�, without an attempt of reconciliation, was �manifestly arbitrary� and �violative of Article 14� of the Constitution. This judgement prevents the future happening of such cases but does is also mend the damage that has already been caused is the question as it is not expressly mentioned anywhere in the judgement neither any provision is made regarding the retrospective applicability of the law.

Whether the judgement delivered in the case Shayara Bano vs Union of India And ors. Ministry Of on 22 August, 2017 AIR SC 4609 in the light of instant triple Talaq (TALAQ E BIDDAT) is applied retrospectively or not?

Time and again in multiple cases like Keshavan Vs State of Bombay 1951 AIR 128, Janardhan Reddy Vs State 1951 AIR 217 court has held that:
It is a settled proposition of law that all laws are deemed to apply prospectively unless either expressly specified to apply retrospectively or intended to have been done so by the legislature.

The latter would be a case of necessary implication and it cannot be inferred lightly.� If the question is considered in the light of the above cited judgement the retrospective applicability is not mentioned in the judgement nor any provision it is expressly mentioned, therefore it can be derived that the judgement can be applicable only prospectively.

When Can A Law Be Made Enforceable?
In a supreme court case Harla vs. The State of Rajasthan (24.09.1951 - SC): AIR 1951 SC 467 it was held, In the absence of any special law or custom, we are of opinion that it would be against the principles of natural justice to permit the subjects of a State to be punished or penalized by laws of which they had no knowledge and of which they could not even with the exercise of reasonable diligence have acquired any knowledge. Natural justice requires that before a law can become operative it must be promulgated or published.

Conclusion
Therefore, in the light of the judgements cited above the judgement delivered in the case of Shayara Bano vs Union of India And ors. Ministry of on 22 August, 2017 AIR 2017 SC 4609 in which pronouncement of instant triple Talaq was declared a punishable offence, cannot be applied retrospectively, unless expressly made retrospective, which implies that in any case pending or already decided regarding the pronouncement of instant triple Talaq by the husband cannot be punished as the act wasn�t notified to be unconstitutional at the time of its commission.