diff --git a/man/org.freedesktop.systemd1.xml b/man/org.freedesktop.systemd1.xml
index 97629c0470..75909aa9e5 100644
--- a/man/org.freedesktop.systemd1.xml
+++ b/man/org.freedesktop.systemd1.xml
@@ -2720,12 +2720,6 @@ node /org/freedesktop/systemd1/unit/avahi_2ddaemon_2eservice {
 
     <!--property RestartUSec is not documented!-->
 
-    <!--property TimeoutStartUSec is not documented!-->
-
-    <!--property TimeoutStopUSec is not documented!-->
-
-    <!--property TimeoutAbortUSec is not documented!-->
-
     <!--property TimeoutStartFailureMode is not documented!-->
 
     <!--property TimeoutStopFailureMode is not documented!-->
@@ -3772,6 +3766,18 @@ node /org/freedesktop/systemd1/unit/avahi_2ddaemon_2eservice {
       <para>Most properties of the Service interface map directly to the corresponding settings in service
       unit files. For the sake of brevity, here's a list of all exceptions only:</para>
 
+      <para><varname>TimeoutStartUSec</varname>, <varname>TimeoutStopUSec</varname> and
+      <varname>TimeoutAbortUSec</varname> contain the start, stop and abort timeouts, in microseconds. Note
+      the slight difference in naming when compared to the matching unit file settings (see
+      <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>7</manvolnum></citerefentry>):
+      these bus properties strictly use microseconds (and thus are suffixed <varname>…USec</varname>) while
+      the unit file settings default to a time unit of seconds (and thus are suffixed
+      <varname>…Sec</varname>), unless a different unit is explicitly specified. This reflects that fact that
+      internally the service manager deals in microsecond units only, and the bus properties are a relatively
+      low-level (binary) concept exposing this. The unit file settings on the other hand are relatively
+      high-level (string-based) concepts and thus support more user friendly time specifications which
+      default to second time units but allow other units too, if specified.</para>
+
       <para><varname>WatchdogTimestamp</varname> and <varname>WatchdogTimestampMonotonic</varname> contain
       <constant>CLOCK_REALTIME</constant>/<constant>CLOCK_MONOTONIC</constant> microsecond timestamps of the
       last watchdog ping received from the service, or 0 if none was ever received.</para>
@@ -9238,8 +9244,6 @@ node /org/freedesktop/systemd1/unit/session_2d1_2escope {
 
     <!--method AttachProcesses is not documented!-->
 
-    <!--property TimeoutStopUSec is not documented!-->
-
     <!--property RuntimeMaxUSec is not documented!-->
 
     <!--property Slice is not documented!-->
diff --git a/man/systemctl.xml b/man/systemctl.xml
index bb3a296645..1c55028837 100644
--- a/man/systemctl.xml
+++ b/man/systemctl.xml
@@ -446,7 +446,11 @@ Jan 12 10:46:45 example.com bluetoothd[8900]: gatt-time-server: Input/output err
             current main process identifier as <literal>MainPID</literal> (which is runtime state), and time settings
             are always exposed as properties ending in the <literal>…USec</literal> suffix even if a matching
             configuration options end in <literal>…Sec</literal>, because microseconds is the normalized time unit used
-            by the system and service manager.</para>
+            internally by the system and service manager.</para>
+
+            <para>For details about many of these properties, see the documentation of the D-Bus interface
+            backing these properties, see
+            <citerefentry><refentrytitle>org.freedesktop.systemd1</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
           </listitem>
         </varlistentry>
         <varlistentry>
diff --git a/man/systemd.time.xml b/man/systemd.time.xml
index 5b7800e78b..79fe9735c4 100644
--- a/man/systemd.time.xml
+++ b/man/systemd.time.xml
@@ -75,6 +75,16 @@
     <para>One can use the <command>timespan</command> command of
     <citerefentry><refentrytitle>systemd-analyze</refentrytitle><manvolnum>1</manvolnum></citerefentry>
     to normalise a textual time span for testing and validation purposes.</para>
+
+    <para>Internally, systemd generally operates with microsecond time granularity, while the default time
+    unit in user-configurable time spans is usually seconds (see above). This disparity becomes visible when
+    comparing the same settings in the (high-level) unit file syntax with the matching (more low-level) D-Bus
+    properties (which are what
+    <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s
+    <command>show</command> command displays). The former typically are suffixed with <literal>…Sec</literal>
+    to indicate the default unit of seconds, the latter are typically suffixed with <literal>…USec</literal>
+    to indicate the underlying low-level time unit, even if they both encapsulate the very same
+    settings.</para>
   </refsect1>
 
   <refsect1>