&gt; What happens when it adjust backwards in time.<p>NTP deliberately makes only very tiny changes gradually when adjusting clock time backwards. Automatic updates also normally abort if the time difference would be more than 1000s (~16m). This is all fairly well-documented.<p><a href="https:&#x2F;&#x2F;www.eecis.udel.edu&#x2F;~mills&#x2F;ntp&#x2F;html&#x2F;index.html" rel="nofollow">https:&#x2F;&#x2F;www.eecis.udel.edu&#x2F;~mills&#x2F;ntp&#x2F;html&#x2F;index.html</a>