diff --git a/src/main/java/org/codelibs/fess/Constants.java b/src/main/java/org/codelibs/fess/Constants.java
index c11958dae..debb238bd 100644
--- a/src/main/java/org/codelibs/fess/Constants.java
+++ b/src/main/java/org/codelibs/fess/Constants.java
@@ -15,6 +15,7 @@
  */
 package org.codelibs.fess;
 
+import java.util.TimeZone;
 import java.util.regex.Pattern;
 
 import org.codelibs.core.CoreLibConstants;
@@ -355,4 +356,6 @@ public class Constants extends CoreLibConstants {
     public static final Integer DEFAULT_DAY_FOR_CLEANUP = 3;
 
     public static final String FESS_CONF_PATH = "fess.conf.path";
+
+    public static final TimeZone TIMEZONE_UTC = TimeZone.getTimeZone("UTC");
 }
diff --git a/src/main/java/org/codelibs/fess/crawler/FessCrawlerThread.java b/src/main/java/org/codelibs/fess/crawler/FessCrawlerThread.java
index 42d18af1e..65499f900 100644
--- a/src/main/java/org/codelibs/fess/crawler/FessCrawlerThread.java
+++ b/src/main/java/org/codelibs/fess/crawler/FessCrawlerThread.java
@@ -42,6 +42,7 @@ import org.codelibs.fess.helper.IndexingHelper;
 import org.codelibs.fess.helper.SambaHelper;
 import org.codelibs.fess.mylasta.direction.FessConfig;
 import org.codelibs.fess.util.ComponentUtil;
+import org.codelibs.fess.util.DocumentUtil;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -111,7 +112,7 @@ public class FessCrawlerThread extends CrawlerThread {
                     return true;
                 }
 
-                final Date expires = (Date) document.get(fessConfig.getIndexFieldExpires());
+                final Date expires = DocumentUtil.getValue(document, fessConfig.getIndexFieldExpires(), Date.class);
                 if (expires != null && expires.getTime() < System.currentTimeMillis()) {
                     final Object idValue = document.get(fessConfig.getIndexFieldId());
                     if (idValue != null) {
@@ -120,7 +121,7 @@ public class FessCrawlerThread extends CrawlerThread {
                     return true;
                 }
 
-                final Date lastModified = (Date) document.get(fessConfig.getIndexFieldLastModified());
+                final Date lastModified = DocumentUtil.getValue(document, fessConfig.getIndexFieldLastModified(), Date.class);
                 if (lastModified == null) {
                     return true;
                 }
diff --git a/src/main/java/org/codelibs/fess/taglib/FessFunctions.java b/src/main/java/org/codelibs/fess/taglib/FessFunctions.java
index f4b2ee997..0cec28c6d 100644
--- a/src/main/java/org/codelibs/fess/taglib/FessFunctions.java
+++ b/src/main/java/org/codelibs/fess/taglib/FessFunctions.java
@@ -142,14 +142,18 @@ public class FessFunctions {
             return null;
         }
         try {
-            return new SimpleDateFormat(Constants.ISO_DATETIME_FORMAT).parse(value);
+            final SimpleDateFormat sdf = new SimpleDateFormat(Constants.ISO_DATETIME_FORMAT);
+            sdf.setTimeZone(Constants.TIMEZONE_UTC);
+            return sdf.parse(value);
         } catch (final ParseException e) {
             return null;
         }
     }
 
     public static String formatDate(final Date date) {
-        return new SimpleDateFormat(Constants.ISO_DATETIME_FORMAT).format(date);
+        final SimpleDateFormat sdf = new SimpleDateFormat(Constants.ISO_DATETIME_FORMAT);
+        sdf.setTimeZone(Constants.TIMEZONE_UTC);
+        return sdf.format(date);
     }
 
     public static String formatDate(final LocalDateTime date) {
diff --git a/src/main/webapp/WEB-INF/crawler/resources/app.xml b/src/main/webapp/WEB-INF/crawler/resources/app.xml
index 418b090c9..a2f092821 100644
--- a/src/main/webapp/WEB-INF/crawler/resources/app.xml
+++ b/src/main/webapp/WEB-INF/crawler/resources/app.xml
@@ -6,7 +6,7 @@
 	<include path="lastaflute_director.xml"/>
 	<include path="fess.xml" />
 
-	<include path="crawler_es.xml" />
+	<include path="crawler.xml" />
 
 	<component name="indexingHelper" class="org.codelibs.fess.helper.IndexingHelper">
 	</component>