What happens if a law is promulgated deeming an act or omission as a crime or increasing the penalty, but the law is temporary or limited to a specific period of time, or if exceptional and unexpected circumstances caused the law to be promulgated?  
In such a case, the expiry of the period set for its application or the forfeiture of the exceptional and unexpected circumstances will not prevent the filing of criminal cases for any crime committed within the expired period, nor preclude the execution of the penalty imposed in accordance with the law.