At any time
Income Tax Amending Act, 1959, Section 4
When the section uses the words "at any time", it means at any time; it does not thereby say that the notice must be issued at any time before the 1959 Act but after a certain other point of time. The other limit is not to be found in the section at all. (S.C. Prashar v. Vasantsen, AIR 1963 SC 1356 (1379,1380)