A person regularly files GST Rerun on quarterly basis. For the quarter ending June 30, he files GSTR-3 on 15 July. He applies for GST cancellation on 16 July. He has no outward supply from 1 July to 15 July. Is he required to file GSTR-1 and GSTR-3B for the period from 1 July to 31 July? If so, when? Since he is a quarterly filer, before applying for cancellation, he cannot file any return for that period on 16 July.