Chapter 3 Operations and Effects of Laws SEC. 9. Effectivity of Executive Issuances. – Executive Issuances shall take effect after fifteen (15) days following the completion of their publication in the Official Gazette or in a newspaper of regional circulation, unless otherwise provided. SEC. 10. Prospectivity of Executive Issuances. - Executive Issuances shall have prospective effect when beneficial to parties affected unless otherwise provided. SEC. 11. Interpretation of Laws and Administrative Issuances. - In the interpretation of a law or an administrative issuance promulgated in all the official languages, the language used in the original text shall control, unless otherwise specifically provided. Only in the event of ambiguity, omission or mistake, may the other texts be consulted. Chapter 4 Regular Holidays and Special Holidays SEC. 12. Observance of Regular and Special Holidays. - Regular holidays and special holidays provided for by laws and issuances of the National Government shall be observed in the Autonomous Region in Muslim Mindanao. SEC. 13. ARMM Holidays. - The ARMM holidays shall be in accordance with MMA Act No. 17 otherwise known as “ARMM Holiday Law” of 1992 and such other holidays promulgated by the Regional Assembly and/or by the Regional Governor. The Regional Governor may proclaim any local special holiday for a particular date and place in accordance with existing laws and issuances. SEC. 14. Pretermission of Holiday. - Where the day, or the last day, for doing any act required or permitted by law falls on a regular holiday or special day, the act may be done on the next succeeding business day. SEC. 15. Official Gazette. – There shall be an official gazette of the Regional Government which will publish all legislative acts and resolutions of a public nature, all executive and administrative issuances of general application, decisions or abstracts of decisions of the Shari‟ah Courts of sufficient importance to be published, documents or classes of documents as maybe required to be published by law and such documents or classes of documents of general application. The official gazette shall be published by the Bureau of Public Information (BPI) monthly in the English language and whenever practicable in Filipino and Arabic. It shall be made available to all national and local agencies upon subscription. The Regional Library shall serve as the official custodian and repository thereof. 6