Article 22 Revised Penal Code
Article 22 of the Revised Penal Code is about Retroactive effect of penal laws. It is under Chapter One (Penalties In General) of Title Three (Penalties) of the Code.
Retroactive effect of penal laws
Penal Laws shall have a retroactive effect insofar as they favor the persons guilty of a felony, who is not a habitual criminal, as this term is defined in Rule 5 of Article 62 of this Code, although at the time of the publication of such laws a final sentence has been pronounced and the convict is serving the same.
See also: Article 21 Revised Penal Code