Pulse-Per-Second API for UNIX-like Operating Systems, Version 1.0

RFC 1589 describes a UNIX kernel implementation model for high- precision time-keeping. This model is meant for use in conjunction with the Network Time Protocol (NTP, RFC 1305), or similar time synchronization protocols. One aspect of this model is an accurate interface to the high-accuracy, one pulse-per-second (PPS) output typically available from precise time sources (such as a GPS or GOES receiver). RFC 1589 did not define an API for managing the PPS facility, leaving implementors without a portable means for using PPS sources. This document specifies such an API.