Section 464(3) in The Bombay Provincial Municipal Corporations Act, 1949
(3)The modification or repeal of a bye-law under sub-section (2) shall take effect, from such date as the [State] Government shall in the said notification direct or, if no such date is specified, from the date of the publication of the said notification in the Official Gazette, except as to anything done or suffered or omitted to be done before such date.
