Index: /trunk/src/org/openstreetmap/josm/gui/download/BookmarkList.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/gui/download/BookmarkList.java	(revision 17720)
+++ /trunk/src/org/openstreetmap/josm/gui/download/BookmarkList.java	(revision 17721)
@@ -6,4 +6,5 @@
 import java.awt.Component;
 import java.awt.GraphicsEnvironment;
+import java.time.ZoneId;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -231,5 +232,5 @@
          */
         public ChangesetBookmark(Changeset cs) {
-            setName(String.format("%d - %tF - %s", cs.getId(), cs.getCreatedAt(), cs.getComment()));
+            setName(String.format("%d - %tF - %s", cs.getId(), cs.getCreatedAt().atZone(ZoneId.systemDefault()), cs.getComment()));
             setIcon(ImageProvider.get("data", "changeset", ImageSizes.SMALLICON));
             setArea(cs.getBounds());
Index: /trunk/test/unit/org/openstreetmap/josm/gui/download/BookmarkListTest.java
===================================================================
--- /trunk/test/unit/org/openstreetmap/josm/gui/download/BookmarkListTest.java	(revision 17721)
+++ /trunk/test/unit/org/openstreetmap/josm/gui/download/BookmarkListTest.java	(revision 17721)
@@ -0,0 +1,33 @@
+// License: GPL. For details, see LICENSE file.
+package org.openstreetmap.josm.gui.download;
+
+import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.RegisterExtension;
+import org.openstreetmap.josm.data.osm.Changeset;
+import org.openstreetmap.josm.testutils.JOSMTestRules;
+
+import java.time.Instant;
+
+/**
+ * Unit test of {@link BookmarkList}
+ */
+class BookmarkListTest {
+
+    /**
+     * Setup test.
+     */
+    @RegisterExtension
+    @SuppressFBWarnings(value = "URF_UNREAD_PUBLIC_OR_PROTECTED_FIELD")
+    public JOSMTestRules test = new JOSMTestRules();
+
+    /**
+     * Unit test of {@link BookmarkList.ChangesetBookmark#ChangesetBookmark(Changeset)}
+     */
+    @Test
+    void testChangeset() {
+        Changeset cs = new Changeset();
+        cs.setCreatedAt(Instant.EPOCH);
+        new BookmarkList.ChangesetBookmark(cs);
+    }
+}