A profit-seeking enterprise that adopts a calendar year basis shall, within the period from May 1 to May 31 of each year, file a tax return with an annual income return providing the items and amounts that make up its business revenue for the preceding year along with details relating to any exemptions and deductions; a profit-seeking enterprise that adopts a special accounting year shall file the return within one month starting from the fifth month after the end of its fiscal year.