Alternate minimum tax certification must be obtained and furnished before the specified audit due date, with elective-regime exclusions. Section 115JC is amended to require a prescribed-form accountant's certificate, certifying that the adjusted total income and the alternate minimum tax are computed in accordance with the Chapter, to be obtained and furnished before the specified date referred to in section 44AB (one month before the return due date); the timing change is effective 1 April 2020. A new proviso excludes persons who have exercised the option under sections 115BAC or 115BAD from applicability, effective 1 April 2021.