Index: /trunk/src/org/openstreetmap/josm/tools/date/DateUtils.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/tools/date/DateUtils.java	(revision 17910)
+++ /trunk/src/org/openstreetmap/josm/tools/date/DateUtils.java	(revision 17911)
@@ -245,5 +245,7 @@
      * @return a new ISO 8601 date format, for date and time.
      * @since 7299
-     */
+     * @deprecated Use {@link Instant#toString()}
+     */
+    @Deprecated
     public static SimpleDateFormat newIsoDateTimeFormat() {
         return new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssX");
Index: /trunk/test/unit/org/openstreetmap/josm/io/OsmJsonReaderTest.java
===================================================================
--- /trunk/test/unit/org/openstreetmap/josm/io/OsmJsonReaderTest.java	(revision 17910)
+++ /trunk/test/unit/org/openstreetmap/josm/io/OsmJsonReaderTest.java	(revision 17911)
@@ -12,5 +12,4 @@
 import java.util.Iterator;
 
-import org.junit.jupiter.api.BeforeAll;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.RegisterExtension;
@@ -23,5 +22,4 @@
 import org.openstreetmap.josm.gui.progress.NullProgressMonitor;
 import org.openstreetmap.josm.testutils.JOSMTestRules;
-import org.openstreetmap.josm.tools.date.DateUtils;
 
 import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
@@ -38,12 +36,4 @@
     @SuppressFBWarnings(value = "URF_UNREAD_PUBLIC_OR_PROTECTED_FIELD")
     public JOSMTestRules test = new JOSMTestRules();
-
-    /**
-     * Setup test
-     */
-    @BeforeAll
-    public static void setUp() {
-        DateUtils.newIsoDateTimeFormat().setTimeZone(DateUtils.UTC);
-    }
 
     /**