We describe the operation of the Standard Time & Frequency Signal (STFS) broadcast via INSAT satellite in the so-called online differential mode. The transmission setup at the Delhi Earth station and the recent version of the STFS decoder are briefly described. Regular data recording carried out at NPL, New Delhi, NRL, Trombay, field station at Mt Abu and ERTL(E), Calcutta have been used in this paper to draw conclusions regarding improvement in time transfer accuracy.