Tax exemption period under Section 10(23FE) extended, deferring statutory expiry and preserving existing notification terms. The Central Government amends the principal CBDT notification under section 10(23FE) by substituting the previously stated expiry date with a new expiry date, thereby extending the period of tax exemption specified in that notification. The amendment is effected under the relevant sub-clause of Explanation 1 to clause (23FE) of section 10 and preserves prior notification terms, while noting applicability except as to acts done or omitted between the fiscal commencement and the present Gazette publication.