Time synchronization is needed in a distributed system for various functions such as ordering of events, recording global state, and fault detection and recovery. Physical synchronization of clocks in a distributed system is the process of adjusting the physical clock of a process based on the clock values of other processes. Logical clocks consider virtual clocks which are advanced at each local event or sending and receiving of messages. Vector clock and matrix clock based synchronizations provide adjusting of the clock of a process by observing the clock values of other processes in the system. In this chapter, we review physical clock, logical clock, vector clock and matrix clock synchronization algorithms and implement them in Python using mpi4py.