Explain ntpdate debugging output

Question

May I know what is meant by "reference time" in the ntpdate -d output?

reference time:    d5cff417.1a961fff  Tue, Sep  3 2013  7:37:27.103

Answer 1

According to the Network Time Protocol Docs:

Reference Timestamp:

This is a 64-bit timestamp established by the server or client host as the timestamp (presumably obtained from a reference clock) most recently used to update the local clock. If the local clock has never been synchronized, the value is zero.