The Civil Code of 1889 and other previous laws shall govern rights originating, under said laws, from acts done or events which took place under their regime, even though this Code may regulate them in a different manner, or may not recognize them. But if a right should be declared for the first time in this Code, it shall be effective at once, even though the act or event which gives rise thereto may have been done or may have occurred under prior legislation, provided said new right does not prejudice or impair any vested or acquired right, of the same origin. (Rule 1)