Extension of tax exemption period under section 10(23FE) prolongs the existing exemption and amends the prior notification. An administrative amendment replaces the expiry date in the opening paragraph of the principal notification granting the income tax exemption under section 10(23FE), extending the statutory exemption period by textual substitution and invoking the explanatory power under the Act; the amendment is subject to a carve out for actions or omissions occurring from the start of the relevant fiscal year until publication.