Mention systemd-timesyncd on Setting the system clock page.

git-svn-id: http://svn.linuxfromscratch.org/LFS/branches/systemd/BOOK@10655 4aa44e1e-78dd-0310-a6d2-fbcd4c07a689

chapter07/clock.xml

@@ -72,4 +72,27 @@ EOF</userinput></screen>
   <note><para>Please note that <command>timedatectl</command> command can
   be used only on a system booted with systemd.</para></note>
 
+  <sect2>
+    <title>Network Time Synchronization</title>
+
+    <para>Starting with version 214, systemd ships a daemon called
+    <command>systemd-timesyncd</command> which can be used to
+    synchronize the system time with remote NTP servers.</para>
+
+    <para>The daemon is not intended as a replacement for the well
+    established NTP daemon, but as a client only implementation
+    of the SNTP protocol which can be used for less advanced
+    tasks and on a resource limited systems.</para>
+
+    <para>To enable the <command>systemd-timesyncd</command> daemon,
+    issue the following command:</para>
+
+<screen role="nodump"><userinput>systemctl enable systemd-timesyncd</userinput></screen>
+
+    <para>The <filename>/etc/systemd/timesyncd.conf</filename> file
+    can be used to change the NTP servers that
+    <command>systemd-timesyncd</command> synchronizes with.</para>
+
+  </sect2>
+
 </sect1>