Index: lams_admin/src/java/org/lamsfoundation/lams/admin/service/ImportService.java
===================================================================
diff -u -rb4c7cf180245db7c4d9d5c600eaf294a4c570286 -rc1fdc839165f8b33f051c1688465022f0d85fc92
--- lams_admin/src/java/org/lamsfoundation/lams/admin/service/ImportService.java	(.../ImportService.java)	(revision b4c7cf180245db7c4d9d5c600eaf294a4c570286)
+++ lams_admin/src/java/org/lamsfoundation/lams/admin/service/ImportService.java	(.../ImportService.java)	(revision c1fdc839165f8b33f051c1688465022f0d85fc92)
@@ -707,7 +707,7 @@
 
 	String timeZoneColumn = parseStringCell(row.getCell(ImportService.TIME_ZONE));
 	user.setTimeZone(
-		TimeZoneUtil.isTimezoneValid(timeZoneColumn) ? timeZoneColumn : TimeZoneUtil.getServerTimezone());
+		TimeZoneUtil.isTimeZoneValid(timeZoneColumn) ? timeZoneColumn : TimeZoneUtil.getServerTimeZone());
 
 	service.updatePassword(user, password);
 
Index: lams_admin/src/java/org/lamsfoundation/lams/admin/web/controller/ConfigController.java
===================================================================
diff -u -rb4c7cf180245db7c4d9d5c600eaf294a4c570286 -rc1fdc839165f8b33f051c1688465022f0d85fc92
--- lams_admin/src/java/org/lamsfoundation/lams/admin/web/controller/ConfigController.java	(.../ConfigController.java)	(revision b4c7cf180245db7c4d9d5c600eaf294a4c570286)
+++ lams_admin/src/java/org/lamsfoundation/lams/admin/web/controller/ConfigController.java	(.../ConfigController.java)	(revision c1fdc839165f8b33f051c1688465022f0d85fc92)
@@ -28,6 +28,7 @@
 import org.lamsfoundation.lams.logevent.LogEvent;
 import org.lamsfoundation.lams.logevent.service.ILogEventService;
 import org.lamsfoundation.lams.security.ISecurityService;
+import org.lamsfoundation.lams.timezone.TimeZoneUtil;
 import org.lamsfoundation.lams.usermanagement.dto.UserDTO;
 import org.lamsfoundation.lams.util.Configuration;
 import org.lamsfoundation.lams.util.ConfigurationKeys;
@@ -45,6 +46,7 @@
 
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpSession;
+import java.time.ZoneId;
 import java.util.LinkedHashMap;
 import java.util.Map;
 import java.util.TimeZone;
@@ -82,7 +84,7 @@
 	smtpAuthTypes.put("ssl", "SSL");
 	request.setAttribute("smtpAuthTypes", smtpAuthTypes);
 
-	request.setAttribute("timezones", TimeZone.getAvailableIDs());
+	request.setAttribute("timezones", TimeZoneUtil.getTimeZones());
 
 	return "config/editconfig";
     }
Index: lams_admin/src/java/org/lamsfoundation/lams/admin/web/controller/UserController.java
===================================================================
diff -u -rb4c7cf180245db7c4d9d5c600eaf294a4c570286 -rc1fdc839165f8b33f051c1688465022f0d85fc92
--- lams_admin/src/java/org/lamsfoundation/lams/admin/web/controller/UserController.java	(.../UserController.java)	(revision b4c7cf180245db7c4d9d5c600eaf294a4c570286)
+++ lams_admin/src/java/org/lamsfoundation/lams/admin/web/controller/UserController.java	(.../UserController.java)	(revision c1fdc839165f8b33f051c1688465022f0d85fc92)
@@ -58,10 +58,10 @@
 
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpSession;
+import java.time.ZoneId;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
-import java.util.TimeZone;
 
 /**
  * @author Jun-Dir Liew
@@ -184,7 +184,7 @@
 		log.debug(e);
 	    }
 
-	    userForm.setTimeZone(TimeZoneUtil.getServerTimezone());
+	    userForm.setTimeZone(TimeZoneUtil.getServerTimeZone());
 	}
 	userForm.setOrgId(org == null ? null : org.getOrganisationId());
 
@@ -198,7 +198,7 @@
 	    request.setAttribute("canSetTwoFactorAuthentication", true);
 	}
 
-	request.setAttribute("timezones", TimeZone.getAvailableIDs());
+	request.setAttribute("timezones", TimeZoneUtil.getTimeZones());
 
 	// for breadcrumb links
 	if (org != null) {
Index: lams_central/src/java/org/lamsfoundation/lams/web/ProfileController.java
===================================================================
diff -u -r85e52bd836773ab33bc41ba2ca0ced5a5f4d4fbb -rc1fdc839165f8b33f051c1688465022f0d85fc92
--- lams_central/src/java/org/lamsfoundation/lams/web/ProfileController.java	(.../ProfileController.java)	(revision 85e52bd836773ab33bc41ba2ca0ced5a5f4d4fbb)
+++ lams_central/src/java/org/lamsfoundation/lams/web/ProfileController.java	(.../ProfileController.java)	(revision c1fdc839165f8b33f051c1688465022f0d85fc92)
@@ -34,6 +34,7 @@
 import org.lamsfoundation.lams.policies.service.IPolicyService;
 import org.lamsfoundation.lams.themes.Theme;
 import org.lamsfoundation.lams.themes.service.IThemeService;
+import org.lamsfoundation.lams.timezone.TimeZoneUtil;
 import org.lamsfoundation.lams.usermanagement.Organisation;
 import org.lamsfoundation.lams.usermanagement.OrganisationType;
 import org.lamsfoundation.lams.usermanagement.SupportedLocale;
@@ -57,6 +58,7 @@
 import org.springframework.web.bind.annotation.RequestMapping;
 
 import javax.servlet.http.HttpServletRequest;
+import java.time.ZoneId;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
@@ -256,7 +258,7 @@
 	}
 	userForm.setUserTheme(userSelectedTheme);
 
-	request.setAttribute("timezones", TimeZone.getAvailableIDs());
+	request.setAttribute("timezones", TimeZoneUtil.getTimeZones());
 
 	return "profile/editprofile";
     }
Index: lams_central/src/java/org/lamsfoundation/lams/web/controller/SignupController.java
===================================================================
diff -u -rb4c7cf180245db7c4d9d5c600eaf294a4c570286 -rc1fdc839165f8b33f051c1688465022f0d85fc92
--- lams_central/src/java/org/lamsfoundation/lams/web/controller/SignupController.java	(.../SignupController.java)	(revision b4c7cf180245db7c4d9d5c600eaf294a4c570286)
+++ lams_central/src/java/org/lamsfoundation/lams/web/controller/SignupController.java	(.../SignupController.java)	(revision c1fdc839165f8b33f051c1688465022f0d85fc92)
@@ -82,7 +82,7 @@
 		user.setLastName(signupForm.getLastName());
 		user.setEmail(signupForm.getEmail());
 		user.setCountry(signupForm.getCountry());
-		user.setTimeZone(TimeZoneUtil.getServerTimezone());
+		user.setTimeZone(TimeZoneUtil.getServerTimeZone());
 
 		if (!ValidationUtil.isPasswordNotUserDetails(signupForm.getPassword(), user)) {
 		    errorMap.add("password", messageService.getMessage("label.password.restrictions"));
Index: lams_common/src/java/org/lamsfoundation/lams/integration/service/IntegrationService.java
===================================================================
diff -u -rb4c7cf180245db7c4d9d5c600eaf294a4c570286 -rc1fdc839165f8b33f051c1688465022f0d85fc92
--- lams_common/src/java/org/lamsfoundation/lams/integration/service/IntegrationService.java	(.../IntegrationService.java)	(revision b4c7cf180245db7c4d9d5c600eaf294a4c570286)
+++ lams_common/src/java/org/lamsfoundation/lams/integration/service/IntegrationService.java	(.../IntegrationService.java)	(revision c1fdc839165f8b33f051c1688465022f0d85fc92)
@@ -504,7 +504,7 @@
 	    user.setCreateDate(new Date());
 	    user.setDisabledFlag(false);
 	    user.setLocale(LanguageUtil.getSupportedLocaleByNameOrLanguageCode(userData[12]));
-	    user.setTimeZone(TimeZoneUtil.getServerTimezone());
+	    user.setTimeZone(TimeZoneUtil.getServerTimeZone());
 	    user.setTheme(service.getDefaultTheme());
 	    service.saveUser(user);
 	}
Index: lams_common/src/java/org/lamsfoundation/lams/timezone/TimeZoneUtil.java
===================================================================
diff -u -rb4c7cf180245db7c4d9d5c600eaf294a4c570286 -rc1fdc839165f8b33f051c1688465022f0d85fc92
--- lams_common/src/java/org/lamsfoundation/lams/timezone/TimeZoneUtil.java	(.../TimeZoneUtil.java)	(revision b4c7cf180245db7c4d9d5c600eaf294a4c570286)
+++ lams_common/src/java/org/lamsfoundation/lams/timezone/TimeZoneUtil.java	(.../TimeZoneUtil.java)	(revision c1fdc839165f8b33f051c1688465022f0d85fc92)
@@ -1,20 +1,29 @@
 package org.lamsfoundation.lams.timezone;
 
-import org.apache.commons.lang.ArrayUtils;
 import org.apache.commons.lang.StringUtils;
 import org.lamsfoundation.lams.util.Configuration;
 import org.lamsfoundation.lams.util.ConfigurationKeys;
 
+import java.time.ZoneId;
+import java.util.List;
 import java.util.TimeZone;
+import java.util.stream.Collectors;
 
 public class TimeZoneUtil {
 
-    public static String getServerTimezone() {
+    private static final List<String> TIMEZONES = ZoneId.getAvailableZoneIds().stream().sorted()
+	    .collect(Collectors.toList());
+
+    public static String getServerTimeZone() {
 	String serverTimezone = Configuration.get(ConfigurationKeys.SERVER_TIMEZONE);
 	return StringUtils.isBlank(serverTimezone) ? TimeZone.getDefault().getID() : serverTimezone;
     }
 
-    public static boolean isTimezoneValid(String timezoneId) {
-	return ArrayUtils.contains(TimeZone.getAvailableIDs(), timezoneId);
+    public static boolean isTimeZoneValid(String timezoneId) {
+	return getTimeZones().contains(timezoneId);
     }
+
+    public static List<String> getTimeZones() {
+	return TIMEZONES;
+    }
 }
\ No newline at end of file
Index: lams_common/src/java/org/lamsfoundation/lams/usermanagement/service/LdapService.java
===================================================================
diff -u -rb4c7cf180245db7c4d9d5c600eaf294a4c570286 -rc1fdc839165f8b33f051c1688465022f0d85fc92
--- lams_common/src/java/org/lamsfoundation/lams/usermanagement/service/LdapService.java	(.../LdapService.java)	(revision b4c7cf180245db7c4d9d5c600eaf294a4c570286)
+++ lams_common/src/java/org/lamsfoundation/lams/usermanagement/service/LdapService.java	(.../LdapService.java)	(revision c1fdc839165f8b33f051c1688465022f0d85fc92)
@@ -150,7 +150,7 @@
 		user.setDisabledFlag(getDisabledBoolean(attrs));
 		user.setCreateDate(new Date());
 		user.setLocale(getLocale(map.get("locale")));
-		user.setTimeZone(TimeZoneUtil.getServerTimezone());
+		user.setTimeZone(TimeZoneUtil.getServerTimeZone());
 		user.setFirstLogin(true);
 		service.saveUser(user);
 		service.logUserCreated(user, (User) null);