Power to grant extension of time for returns, etc

The assessing authority may, in his discretion, in the case of any person or class of persons, extend the date before which the return under sub-section (1) or sub-section (2) of section 4 has to be furnished or, on application by an assessee, allow him such extension or extensions of time as the authority thinks fit to furnish the return or comply with the terms of a notice under this Act.