Article 57 defines the Tax Period for Corporate Tax purposes. It states that a Taxable Person's Tax Period is their Financial Year, or a part thereof, for which a Tax Return is required. The article further defines the Financial Year as either the Gregorian calendar year (January to December) or the specific twelve-month period for which the Taxable Person prepares its financial statements. This definition provides crucial flexibility, allowing businesses to align their tax reporting cycle with their established financial reporting cycle, ensuring consistency between accounting and tax compliance obligations under the law.