Later date specification for definition clause - 31st May 1966 designated as the operative reference date under income tax rules. The Central Government, by Notification No. S.O.289 dated 19-1-1967, specifies a later date for the temporal reference used in the definition provision of the Income-tax Act, designating 31st May 1966 as the later date to be applied for determining the period referred to in the Act's definition clause.