diff --git a/scm-webapp/src/main/java/sonia/scm/upgrade/ClientDateFormatConverter.java b/scm-webapp/src/main/java/sonia/scm/upgrade/ClientDateFormatConverter.java
new file mode 100644
index 0000000000..f586ec1a18
--- /dev/null
+++ b/scm-webapp/src/main/java/sonia/scm/upgrade/ClientDateFormatConverter.java
@@ -0,0 +1,138 @@
+/**
+ * Copyright (c) 2010, Sebastian Sdorra All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer. 2. Redistributions in
+ * binary form must reproduce the above copyright notice, this list of
+ * conditions and the following disclaimer in the documentation and/or other
+ * materials provided with the distribution. 3. Neither the name of SCM-Manager;
+ * nor the names of its contributors may be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * http://bitbucket.org/sdorra/scm-manager
+ *
+ */
+
+
+
+package sonia.scm.upgrade;
+
+//~--- non-JDK imports --------------------------------------------------------
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+//~--- JDK imports ------------------------------------------------------------
+
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+/**
+ *
+ * @author Sebastian Sdorra
+ */
+public class ClientDateFormatConverter
+{
+
+  /** Field description */
+  private static final String SINGLECHAR_REGEX = "(^|[^%s])[%s]($|[^%s])";
+
+  /**
+   * the logger for DateFormatConverter
+   */
+  private static final Logger logger =
+    LoggerFactory.getLogger(ClientDateFormatConverter.class);
+
+  //~--- methods --------------------------------------------------------------
+
+  /**
+   * Documentations:
+   * - Extjs: http://trac.geoext.org/browser/ext/3.4.0/docs/source/Date.html
+   * - Moments: http://momentjs.com/docs/#/displaying/format/
+   *
+   *
+   * @param value
+   *
+   * @return
+   */
+  public static String extjsToMoments(String value)
+  {
+    logger.trace(
+      "try to convert extjs date format \"{}\" to moments date format", value);
+
+    String result = replaceDateFormatChars(value, "d", "DD");
+
+    result = replaceDateFormatChars(result, "D", "ddd");
+    result = replaceDateFormatChars(result, "j", "D");
+    result = replaceDateFormatChars(result, "l", "dddd");
+
+    // no replacement found for 1-7, only 0-6 found
+    result = replaceDateFormatChars(result, "N", "d");
+    result = replaceDateFormatChars(result, "w", "d");
+    result = replaceDateFormatChars(result, "z", "DDDD");
+    result = replaceDateFormatChars(result, "W", "ww");
+    result = replaceDateFormatChars(result, "M", "MMM");
+    result = replaceDateFormatChars(result, "F", "MMMM");
+    result = replaceDateFormatChars(result, "m", "MM");
+    result = replaceDateFormatChars(result, "n", "M");
+    result = replaceDateFormatChars(result, "Y", "YYYY");
+    result = replaceDateFormatChars(result, "o", "YYYY");
+    result = replaceDateFormatChars(result, "y", "YY");
+    result = replaceDateFormatChars(result, "H", "HH");
+    result = replaceDateFormatChars(result, "h", "hh");
+    result = replaceDateFormatChars(result, "g", "h");
+    result = replaceDateFormatChars(result, "G", "H");
+    result = replaceDateFormatChars(result, "i", "mm");
+    result = replaceDateFormatChars(result, "s", "ss");
+    result = replaceDateFormatChars(result, "O", "ZZ");
+    result = replaceDateFormatChars(result, "P", "Z");
+    result = replaceDateFormatChars(result, "T", "z");
+
+    logger.debug(
+      "converted extjs date format \"{}\" to moments date format \"{}\"", value,
+      result);
+
+    return result;
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @param value
+   * @param c
+   * @param replacement
+   *
+   * @return
+   */
+  private static String replaceDateFormatChars(String value, String c,
+    String replacement)
+  {
+    Pattern p = Pattern.compile(String.format(SINGLECHAR_REGEX, c, c, c));
+    StringBuffer buffer = new StringBuffer();
+    Matcher m = p.matcher(value);
+
+    while (m.find())
+    {
+      m.appendReplacement(buffer, "$1" + replacement + "$2");
+    }
+
+    m.appendTail(buffer);
+
+    return buffer.toString();
+  }
+}
diff --git a/scm-webapp/src/main/java/sonia/scm/upgrade/ClientDateFormatUpgradeHandler.java b/scm-webapp/src/main/java/sonia/scm/upgrade/ClientDateFormatUpgradeHandler.java
new file mode 100644
index 0000000000..d335c3f719
--- /dev/null
+++ b/scm-webapp/src/main/java/sonia/scm/upgrade/ClientDateFormatUpgradeHandler.java
@@ -0,0 +1,158 @@
+/**
+ * Copyright (c) 2010, Sebastian Sdorra All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer. 2. Redistributions in
+ * binary form must reproduce the above copyright notice, this list of
+ * conditions and the following disclaimer in the documentation and/or other
+ * materials provided with the distribution. 3. Neither the name of SCM-Manager;
+ * nor the names of its contributors may be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * http://bitbucket.org/sdorra/scm-manager
+ *
+ */
+
+
+
+package sonia.scm.upgrade;
+
+//~--- non-JDK imports --------------------------------------------------------
+
+import com.google.common.io.Files;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import org.w3c.dom.Document;
+import org.w3c.dom.Node;
+import org.w3c.dom.NodeList;
+
+import sonia.scm.SCMContext;
+import sonia.scm.plugin.PluginVersion;
+
+//~--- JDK imports ------------------------------------------------------------
+
+import java.io.File;
+
+import javax.xml.parsers.DocumentBuilder;
+import javax.xml.parsers.DocumentBuilderFactory;
+
+/**
+ *
+ * @author Sebastian Sdorra
+ */
+public class ClientDateFormatUpgradeHandler extends XmlUpgradeHandler
+{
+
+  /**
+   * the logger for ClientDateFormatUpgradeHandler
+   */
+  private static final Logger logger =
+    LoggerFactory.getLogger(ClientDateFormatUpgradeHandler.class);
+
+  //~--- methods --------------------------------------------------------------
+
+  /**
+   * Method description
+   *
+   *
+   * @param homeDirectory
+   * @param configDirectory
+   * @param oldVersion
+   * @param newVersion
+   */
+  @Override
+  public void doUpgrade(File homeDirectory, File configDirectory,
+    PluginVersion oldVersion, PluginVersion newVersion)
+  {
+    if (oldVersion.isOlder("1.23"))
+    {
+      if (logger.isInfoEnabled())
+      {
+        logger.info("data format is older than 1.23, upgrade to version {}",
+          SCMContext.getContext().getVersion());
+      }
+
+      updateClientDateFormat(homeDirectory, configDirectory);
+    }
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @param document
+   */
+  private void fixClientDateFormat(Document document)
+  {
+    NodeList nodes = document.getElementsByTagName("dateFormat");
+
+    if (nodes != null)
+    {
+      for (int i = 0; i < nodes.getLength(); i++)
+      {
+        Node node = nodes.item(i);
+        String value = node.getTextContent();
+
+        value = ClientDateFormatConverter.extjsToMoments(value);
+        node.setTextContent(value);
+      }
+    }
+  }
+
+  /**
+   * Method description
+   *
+   *
+   * @param baseDirectory
+   * @param configDirectory
+   *
+   * @throws IOException
+   */
+  private void updateClientDateFormat(File baseDirectory, File configDirectory)
+  {
+    File configFile = new File(configDirectory, "config.xml");
+
+    if (configFile.exists())
+    {
+      try
+      {
+
+        // backup config.xml
+        File backupDirectory = createBackupDirectory(baseDirectory,
+                                 "upgrade to version {0}");
+
+        Files.copy(configFile, new File(backupDirectory, "config.xml"));
+
+        // change dateformat
+
+        DocumentBuilder builder =
+          DocumentBuilderFactory.newInstance().newDocumentBuilder();
+        Document document = builder.parse(configFile);
+
+        fixClientDateFormat(document);
+        writeDocument(document, configFile);
+      }
+      catch (Exception ex)
+      {
+        logger.error("could not parse document", ex);
+      }
+    }
+
+  }
+}
diff --git a/scm-webapp/src/test/java/sonia/scm/upgrade/ClientDateFormatConverterTest.java b/scm-webapp/src/test/java/sonia/scm/upgrade/ClientDateFormatConverterTest.java
new file mode 100644
index 0000000000..ea5bd29514
--- /dev/null
+++ b/scm-webapp/src/test/java/sonia/scm/upgrade/ClientDateFormatConverterTest.java
@@ -0,0 +1,65 @@
+/**
+ * Copyright (c) 2010, Sebastian Sdorra All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer. 2. Redistributions in
+ * binary form must reproduce the above copyright notice, this list of
+ * conditions and the following disclaimer in the documentation and/or other
+ * materials provided with the distribution. 3. Neither the name of SCM-Manager;
+ * nor the names of its contributors may be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR
+ * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * http://bitbucket.org/sdorra/scm-manager
+ *
+ */
+
+
+
+package sonia.scm.upgrade;
+
+//~--- non-JDK imports --------------------------------------------------------
+
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+
+import static sonia.scm.upgrade.ClientDateFormatConverter.extjsToMoments;
+
+/**
+ *
+ * @author Sebastian Sdorra
+ */
+public class ClientDateFormatConverterTest
+{
+
+  /**
+   * Method description
+   *
+   */
+  @Test
+  public void testExtjsToMoments()
+  {
+    assertEquals("YYYY-MM-DD", extjsToMoments("Y-m-d"));
+    assertEquals("HH:mm:ss", extjsToMoments("H:i:s"));
+    assertEquals("YYYY-MM-DD HH:mm:ss", extjsToMoments("Y-m-d H:i:s"));
+    assertEquals("YYYY/MM/DD", extjsToMoments("Y/m/d"));
+    assertEquals("MMMM D, YYYY, h:mm a", extjsToMoments("F j, Y, g:i a"));
+
+    // with time ago pattern
+    assertEquals("YYYY-MM-DD {0}", extjsToMoments("Y-m-d {0}"));
+  }
+}