diff --git a/man/systemctl.xml b/man/systemctl.xml
index 1c14909523..53acb083b2 100644
--- a/man/systemctl.xml
+++ b/man/systemctl.xml
@@ -2305,6 +2305,13 @@ Jan 12 10:46:45 example.com bluetoothd[8900]: gatt-time-server: Input/output err
             </varlistentry>
           </variablelist>
 
+          <variablelist>
+            <varlistentry>
+              <term><option>unix</option></term>
+              <listitem><para><literal>@seconds-since-the-epoch</literal></para></listitem>
+            </varlistentry>
+          </variablelist>
+
           <variablelist>
             <varlistentry>
               <term><option>us</option></term>
diff --git a/src/systemctl/systemctl.c b/src/systemctl/systemctl.c
index 9031e685ea..0489796a75 100644
--- a/src/systemctl/systemctl.c
+++ b/src/systemctl/systemctl.c
@@ -296,11 +296,8 @@ static int systemctl_help(void) {
                "     --boot-loader-entry=NAME\n"
                "                         Boot into a specific boot loader entry on next boot\n"
                "     --plain             Print unit dependencies as a list instead of a tree\n"
-               "     --timestamp=FORMAT  Change format of printed timestamps.\n"
-               "                         'pretty' (default): 'Day YYYY-MM-DD HH:MM:SS TZ\n"
-               "                         'us': 'Day YYYY-MM-DD HH:MM:SS.UUUUUU TZ\n"
-               "                         'utc': 'Day YYYY-MM-DD HH:MM:SS UTC\n"
-               "                         'us+utc': 'Day YYYY-MM-DD HH:MM:SS.UUUUUU UTC\n"
+               "     --timestamp=FORMAT  Change format of printed timestamps (pretty, unix,\n"
+               "                             us, utc, us+utc)\n"
                "     --read-only         Create read-only bind mount\n"
                "     --mkdir             Create directory before mounting, if missing\n"
                "     --marked            Restart/reload previously marked units\n"