diff --git a/src/main/java/com/googlesource/gerrit/plugins/reviewnotes/CreateReviewNotes.java b/src/main/java/com/googlesource/gerrit/plugins/reviewnotes/CreateReviewNotes.java
index abaf4aa..3bd9a3b 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/reviewnotes/CreateReviewNotes.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/reviewnotes/CreateReviewNotes.java
@@ -230,7 +230,7 @@
 
   @Nullable
   private ObjectId createNoteContent(ChangeNotes notes, PatchSet ps) throws IOException {
-    HeaderFormatter fmt = new HeaderFormatter(gerritServerIdent.getTimeZone(), anonymousCowardName);
+    HeaderFormatter fmt = new HeaderFormatter(gerritServerIdent.getZoneId(), anonymousCowardName);
     if (ps != null) {
       try {
         createCodeReviewNote(notes, ps, fmt);
diff --git a/src/main/java/com/googlesource/gerrit/plugins/reviewnotes/HeaderFormatter.java b/src/main/java/com/googlesource/gerrit/plugins/reviewnotes/HeaderFormatter.java
index 84b4a64..8597457 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/reviewnotes/HeaderFormatter.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/reviewnotes/HeaderFormatter.java
@@ -24,10 +24,10 @@
 import com.google.gerrit.entities.Project;
 import com.google.gerrit.server.config.UrlFormatter;
 import java.time.Instant;
+import java.time.ZoneId;
 import java.time.format.DateTimeFormatter;
 import java.util.Locale;
 import java.util.Optional;
-import java.util.TimeZone;
 
 /**
  * Formatters for code review note headers.
@@ -42,11 +42,11 @@
   private final String anonymousCowardName;
   private final StringBuilder sb = new StringBuilder();
 
-  HeaderFormatter(TimeZone tz, String anonymousCowardName) {
+  HeaderFormatter(ZoneId zoneid, String anonymousCowardName) {
     rfc2822DateFormatter =
         DateTimeFormatter.ofPattern("EEE, dd MMM yyyy HH:mm:ss Z")
             .withLocale(Locale.US)
-            .withZone(tz.toZoneId());
+            .withZone(zoneid);
     this.anonymousCowardName = anonymousCowardName;
   }