A method for synchronizing the times of a master clock provided in the master station and slave clocks provided in the slave stations in a data transmission and receiving system consisting of the master station as a data transmission control station and slave station and/or stations for two-way data transmission. An encoded time survey command including master clock time is transmitted from the master station to each slave station. This is followed by an encoded response from each slave station which includes the slave clock time, from which the transmission delay to and from the slave station is determined along with the time difference between master and slave clocks. Time correction data is then transmitted to correct the time of the slave station clock.