In this study, an innovative distributed method for achieving external clock synchronization is presented. Based on discrete-time clock models, it can realize synchronization of clocks while enabling their time to change at the same pace simultaneously. Stronger robustness against noisy measurements and clock rate drifts is gained by combining both controller and estimator design methods into the protocol. Additionally, a specifically designed communication scheme is proposed to make our protocols independent on global physical time. To render our protocols more practical, the control variable for clock synchronization is ensured bounded and a stopping criterion for implementation of the protocols is established. Finally, performance of the method is illustrated by certain numerical simulations.