Do laws have retroactive effect?

Article 4 of New Civil Code. Laws shall have no retroactive effect, unless the contrary is provided.

General Rule: All statutes are to be construed as having only prospective operation.

Exceptions: (G.R. No. 160352)

[1] Laws expressly made retrospective in application;

[1a] except in cases of ex post facto laws (United States. v. Diaz Conde, 42 Phil. 766 [1922]);
[1b] and except in cases impairment of obligation of contract (Asiatic Petroleum, Co. v. Llanes, 49 Phil. 466 [1926]);

[2] Procedural laws, prescribing rules and forms of procedures of enforcing rights or obtaining redress for their invasion (Romero v. Court of Appeals, G.R. No. 142803, November 20, 2007, 537 SCRA 643; Subido, Jr. v. Sandiganbayan, 334 Phil. 346 [1997]);

[3] Curative statutes which cure errors and irregularities and validate judicial or administrative proceedings, acts of public officers, or private deeds and contracts that otherwise would not produce their intended consequences due to some statutory disability or failure to comply with technical rules (Government of the Philippine Islands v. Municipality of Binalonan, 32 Phil. 634 [1915]);

[4] Laws interpreting others;

[5] Laws creating new rights (Bona v. Briones, 38 Phil. 276 [1918]), and;

[6] Penal statutes insofar as they favor the accused who is not a habitual criminal (Article 22, Revised Penal Code).