Is there any specific date mentioned when these changes were implemented?
Yes, there are specific dates mentioned when these changes were implemented. The changes are as follows:

1. (c) and (d): These changes were made by the Constitution (Forty-fourth Amendment) Act, 1978, s. 4, which came into effect on 20-6-1979.
2. (e): This change was made by the Constitution (Forty-second Amendment) Act, 1976, s. 3, and it was implemented from 3-1-1977.
3. The sub-heading "Right to Property" omission: It happened with the enactment of the Constitution (Forty-fourth Amendment) Act, 1978, s. 5, which came into effect on 20-6-1979.
4. Insertion by the Constitution (First Amendment) Act, 1951, s. 4: This change was made with retrospective effect.
5. Substitution of clause (1) by the Constitution (Fourth Amendment) Act, 1955, s. 3: This change also came into effect with retrospective effect.