Patents Act, 1970
45. Date of patent
(1) Subject to the other provisions contained in this Act, every patent shall be dated as of the date on which the complete specification was filed:
PROVIDED that a patent which is granted in pursuance of an application to which any directions issued under section 78C of the Indian Patents and Designs Act, 1911 (2 of 1911), applied immediately before the commencement of this Act, shall be dated as of the date of the filing of the complete specification or the date of such commencement whichever is later.
(2) The date of every patent be entered in the register.
(3) Notwithstanding anything contained in this section, no suit or other proceeding shall be commenced or prosecuted in respect of an infringement committed before the date of advertisement of the acceptance of the complete specification.