Network Time Protocol Version 5

The Network Time Protocol (NTP) is a widely deployed protocol that allows hosts to obtain the current time of day from time servers. This document specifies version 5 of the protocol (NTPv5), which adopts a client-server model as its sole mode of operation. Legacy operational modes supported in earlier versions have been removed to improve protocol robustness and clarity. While this specification defines the protocol used for time distribution, it does not define the algorithms or heuristics employed by clients to determine or adjust their local time.