Ensure DSpace defaults to UTC time zone in all code / tests. This is necessary so that Spring / Hibernate don't auto-switch timezones when reading from database.

dspace-api/src/main/java/org/dspace/app/bulkaccesscontrol/BulkAccessControl.java

@@ -18,6 +18,7 @@ import java.io.InputStream;
 import java.sql.SQLException;
 import java.text.DateFormat;
 import java.text.SimpleDateFormat;
+import java.time.ZoneOffset;
 import java.util.Arrays;
 import java.util.Date;
 import java.util.Iterator;
@@ -154,7 +155,7 @@ public class BulkAccessControl extends DSpaceRunnable<BulkAccessControlScriptCon
         }
 
         ObjectMapper mapper = new ObjectMapper();
-        mapper.setTimeZone(TimeZone.getTimeZone("UTC"));
+        mapper.setTimeZone(TimeZone.getTimeZone(ZoneOffset.UTC));
         BulkAccessControlInput accessControl;
         context = new Context(Context.Mode.BATCH_EDIT);
         setEPerson(context);

dspace-api/src/main/java/org/dspace/util/DateMathParser.java

@@ -13,6 +13,7 @@ import java.time.LocalDate;
 import java.time.LocalDateTime;
 import java.time.LocalTime;
 import java.time.ZoneId;
+import java.time.ZoneOffset;
 import java.time.ZonedDateTime;
 import java.time.format.DateTimeFormatter;
 import java.time.format.DateTimeFormatterBuilder;
@@ -107,7 +108,7 @@ public class DateMathParser {
 
     private static final Logger LOG = LogManager.getLogger();
 
-    public static final TimeZone UTC = TimeZone.getTimeZone("UTC");
+    public static final TimeZone UTC = TimeZone.getTimeZone(ZoneOffset.UTC);
 
     /**
      * Default TimeZone for DateMath rounding (UTC)

dspace-api/src/test/java/org/dspace/AbstractDSpaceIntegrationTest.java

@@ -12,6 +12,7 @@ import static org.junit.Assert.fail;
 import java.io.IOException;
 import java.net.URL;
 import java.sql.SQLException;
+import java.time.ZoneOffset;
 import java.util.Properties;
 import java.util.TimeZone;
 
@@ -73,8 +74,10 @@ public class AbstractDSpaceIntegrationTest {
             //Stops System.exit(0) throws exception instead of exitting
             System.setSecurityManager(new NoExitSecurityManager());
 
-            //set a standard time zone for the tests
-            TimeZone.setDefault(TimeZone.getTimeZone("Europe/Dublin"));
+            // All tests should assume UTC timezone by default (unless overridden in the test itself)
+            // This ensures that Spring doesn't attempt to change the timezone of dates that are read from the
+            // database (via Hibernate). We store all dates in the database as UTC.
+            TimeZone.setDefault(TimeZone.getTimeZone(ZoneOffset.UTC));
 
             //load the properties of the tests
             testProps = new Properties();

dspace-api/src/test/java/org/dspace/AbstractDSpaceTest.java

@@ -12,6 +12,7 @@ import static org.junit.Assert.fail;
 import java.io.IOException;
 import java.net.URL;
 import java.sql.SQLException;
+import java.time.ZoneOffset;
 import java.util.Properties;
 import java.util.TimeZone;
 
@@ -82,8 +83,10 @@ public class AbstractDSpaceTest {
     @BeforeClass
     public static void initKernel() {
         try {
-            //set a standard time zone for the tests
-            TimeZone.setDefault(TimeZone.getTimeZone("Europe/Dublin"));
+            // All tests should assume UTC timezone by default (unless overridden in the test itself)
+            // This ensures that Spring doesn't attempt to change the timezone of dates that are read from the
+            // database (via Hibernate). We store all dates in the database as UTC.
+            TimeZone.setDefault(TimeZone.getTimeZone(ZoneOffset.UTC));
 
             //load the properties of the tests
             testProps = new Properties();

dspace-server-webapp/src/main/java/org/dspace/app/rest/Application.java

@@ -9,7 +9,10 @@ package org.dspace.app.rest;
 
 import java.io.IOException;
 import java.sql.SQLException;
+import java.time.ZoneOffset;
 import java.util.List;
+import java.util.TimeZone;
+import javax.annotation.PostConstruct;
 import javax.servlet.Filter;
 
 import org.dspace.app.rest.filter.DSpaceRequestContextFilter;
@@ -262,4 +265,12 @@ public class Application extends SpringBootServletInitializer {
             }
         };
     }
+
+    @PostConstruct
+    public void setDefaultTimezone() {
+        // Set the default timezone in Spring Boot to UTC.
+        // This ensures that Spring Boot doesn't attempt to change the timezone of dates that are read from the
+        // database (via Hibernate). We store all dates in the database as UTC.
+        TimeZone.setDefault(TimeZone.getTimeZone(ZoneOffset.UTC));
+    }
 }