“Two Judge Bench in State Bank’s Staff Union (Madras Circle) v. Union of India, (2005) 7 SCC 584 had occasion to examine the concept. Further in Jay Mahakali Rolling Mills v. Union of India, (2007) 12 SCC 198 following has been laid down:
“Retrospective means looking backward, contemplating what is past, having reference to a statute or things existing before the statute in question. Retrospective law means a law which looks backward or contemplates the past; one, which is made to affect acts or facts occurring, or rights occurring, before it comes into force. Retroactive statute means a statute, which creates a new obligation on transactions or considerations or destroys or impairs vested rights.”
Retroactivity in the context of the statute consists application of new rule of law to a transaction which has been completed before the rule was promulgated.”
– Hon’ble Justice Ashok Bhushan, M/s. Shanti Conductors (P) Ltd. v. Assam State Electricity Board, [Civil appeal Nos. 8442-8443 of 2016].