diff --git a/java/org/apache/catalina/valves/AbstractAccessLogValve.java b/java/org/apache/catalina/valves/AbstractAccessLogValve.java
index 360c1ebbd91c..8c1231d1936f 100644
--- a/java/org/apache/catalina/valves/AbstractAccessLogValve.java
+++ b/java/org/apache/catalina/valves/AbstractAccessLogValve.java
@@ -2155,6 +2155,20 @@ protected AccessLogElement createAccessLogElement(String name, char pattern) {
                 return new RemoteAddrElement(name);
             case 'c':
                 return new CookieElement(name);
+            case 'D':
+                if ("ns".equals(name)) {
+                    return new ElapsedTimeElement(ElapsedTimeElement.Style.NANOSECONDS);
+                } else if ("us".equals(name)) {
+                    return new ElapsedTimeElement(ElapsedTimeElement.Style.MICROSECONDS);
+                } else if ("ms".equals(name)) {
+                    return new ElapsedTimeElement(ElapsedTimeElement.Style.MILLISECONDS);
+                } else if ("s".equals(name)) {
+                    return new ElapsedTimeElement(ElapsedTimeElement.Style.SECONDS);
+                } else if ("fracsec".equals(name)) {
+                    return new ElapsedTimeElement(ElapsedTimeElement.Style.SECONDS_FRACTIONAL);
+                } else {
+                    return new StringElement("???" + name + "???");
+                }
             case 'i':
                 return new HeaderElement(name);
             case 'L':
@@ -2180,10 +2194,12 @@ protected AccessLogElement createAccessLogElement(String name, char pattern) {
                     return new ElapsedTimeElement(ElapsedTimeElement.Style.MICROSECONDS);
                 } else if ("ms".equals(name)) {
                     return new ElapsedTimeElement(ElapsedTimeElement.Style.MILLISECONDS);
+                } else if ("s".equals(name)) {
+                    return new ElapsedTimeElement(ElapsedTimeElement.Style.SECONDS);
                 } else if ("fracsec".equals(name)) {
                     return new ElapsedTimeElement(ElapsedTimeElement.Style.SECONDS_FRACTIONAL);
                 } else {
-                    return new ElapsedTimeElement(ElapsedTimeElement.Style.SECONDS);
+                    return new StringElement("???" + name + "???");
                 }
             default:
                 return new StringElement("???");
@@ -2199,6 +2215,8 @@ protected AccessLogElement createAccessLogElement(String name, char pattern) {
      */
     protected AccessLogElement createAccessLogElement(char pattern) {
         switch (pattern) {
+            case '%':
+                return new StringElement("%");
             case 'a':
                 return new RemoteAddrElement();
             case 'A':
diff --git a/java/org/apache/catalina/valves/ExtendedAccessLogValve.java b/java/org/apache/catalina/valves/ExtendedAccessLogValve.java
index 2bdb9f1ac7fc..ef272c1d0ad4 100644
--- a/java/org/apache/catalina/valves/ExtendedAccessLogValve.java
+++ b/java/org/apache/catalina/valves/ExtendedAccessLogValve.java
@@ -518,10 +518,12 @@ protected AccessLogElement getLogElement(String token, PatternTokenizer tokenize
                             return new ElapsedTimeElement(ElapsedTimeElement.Style.MICROSECONDS);
                         } else if ("ms".equals(nextToken)) {
                             return new ElapsedTimeElement(ElapsedTimeElement.Style.MILLISECONDS);
+                        } else if ("s".equals(nextToken)) {
+                            return new ElapsedTimeElement(ElapsedTimeElement.Style.SECONDS);
                         } else if ("fracsec".equals(nextToken)) {
                             return new ElapsedTimeElement(ElapsedTimeElement.Style.SECONDS_FRACTIONAL);
                         } else {
-                            return new ElapsedTimeElement(ElapsedTimeElement.Style.SECONDS);
+                            return new StringElement("???" + nextToken + "???");
                         }
                     } else {
                         return new ElapsedTimeElement(ElapsedTimeElement.Style.SECONDS);
diff --git a/test/org/apache/catalina/valves/TestAccessLogValve.java b/test/org/apache/catalina/valves/TestAccessLogValve.java
index 49784e642118..08e5630252f0 100644
--- a/test/org/apache/catalina/valves/TestAccessLogValve.java
+++ b/test/org/apache/catalina/valves/TestAccessLogValve.java
@@ -90,6 +90,7 @@ public class TestAccessLogValve extends TomcatBaseTest {
     public static Collection<Object[]> parameters() {
         List<Object[]> parameterSets = new ArrayList<>();
 
+        parameterSets.add(new Object[] {"pct-pct", TEXT_TYPE, "/", "%%", "%"});
         parameterSets.add(new Object[] {"pct-a", TEXT_TYPE, "/", "%a", LOCAL_IP_PATTERN});
         parameterSets.add(new Object[] {"pct-a", JSON_TYPE, "/", "%a", "\\{\"remoteAddr\":\"" + LOCAL_IP_PATTERN + "\"\\}"});
         parameterSets.add(new Object[] {"pct-A", TEXT_TYPE, "/", "%A", IP_PATTERN});
diff --git a/webapps/docs/changelog.xml b/webapps/docs/changelog.xml
index bd8a956041f2..a2e1f1e9d562 100644
--- a/webapps/docs/changelog.xml
+++ b/webapps/docs/changelog.xml
@@ -178,6 +178,10 @@
         Ensure <code>RealmBase</code> finds all matching extension based
         security constraints. (markt)
       </fix>
+      <add>
+        Add <code>%%</code> in AccessLogValve pattern. Align <code>%{xxx}D</code> modifiers with <code>%{xxx}T</code>.
+        Pull request <pr>1003</pr> provided by effhaa.
+      </add>
     </changelog>
   </subsection>
   <subsection name="Coyote">
@@ -5658,4 +5662,3 @@
 </section>
 </body>
 </document>
-
diff --git a/webapps/docs/config/valve.xml b/webapps/docs/config/valve.xml
index fb19da1ce854..6ad322e86ca9 100644
--- a/webapps/docs/config/valve.xml
+++ b/webapps/docs/config/valve.xml
@@ -282,6 +282,7 @@
     the current request and response.  The following pattern codes are
     supported:</p>
     <ul>
+    <li><b><code>%%</code></b> - Literal '%' character</li>
     <li><b><code>%a</code></b> - Remote IP address.
         See also <code>%{xxx}a</code> below.</li>
     <li><b><code>%A</code></b> - Local IP address</li>