  Time serves as the foundation of modern society and will continue to grow in
value in the future world. Unlike previous research papers, authors delve into
various time sources, ranging from atomic time and GPS time to quartz time.
Specifically, we explore the time uncertainty associated with the four major
Global Navigation Satellite Systems. In existing time synchronization
simulations provide partial usages. However, our research introduces a
comprehensive and precise time synchronization simulation named P-TimeSync,
leading to a better understanding of time synchronization in distributed
environments. It is a state-of-the-art simulation tool for time because (1) it
can simulate atomic clocks and quartz clocks with user-defined software clock
algorithms, (2) the simulation provides nanosecond-level precision time across
different network propagation paths and distances, (3) the tool offers a
visualization platform with classic algorithms for distributed time
synchronization, such as Cristian's algorithm and Berkeley algorithm. The
simulation easily allows for the redefinition of configurations and functions,
supporting advanced research and development. The simulation tool could be
downloaded via the website: https://github.com/rui5097/purdue_timesync
