A deduction of one fifth of the period of his sentence shall be granted to any prisoner who, having evaded his preventive imprisonment or the service of his sentence under the circumstances mentioned in Article 158 of this Code, gives himself up to the authorities within 48 hours following the issuance of a proclamation announcing the passing away of the calamity or catastrophe referred to in said article. A deduction of two-fifths of the period of his sentence shall be granted in case said prisoner chose to stay in the place of his confinement notwithstanding the existence of a calamity or catastrophe enumerated in Article 158 of this Code.
This Article shall apply to any prisoner whether undergoing preventive imprisonment or serving sentence.