diff --git a/google-cloud-bigquerystorage/src/main/java/com/google/cloud/bigquery/storage/v1/JsonToProtoMessage.java b/google-cloud-bigquerystorage/src/main/java/com/google/cloud/bigquery/storage/v1/JsonToProtoMessage.java
index ba388fc3d..c7c63aa6f 100644
--- a/google-cloud-bigquerystorage/src/main/java/com/google/cloud/bigquery/storage/v1/JsonToProtoMessage.java
+++ b/google-cloud-bigquerystorage/src/main/java/com/google/cloud/bigquery/storage/v1/JsonToProtoMessage.java
@@ -93,14 +93,11 @@ public class JsonToProtoMessage implements ToProtoConverter<Object> {
           .appendLiteral(' ')
           .optionalEnd()
           .optionalStart()
-          .appendOffset("+HH:MM", "+00:00")
+          .appendZoneOrOffsetId()
           .optionalEnd()
           .optionalStart()
           .appendZoneText(TextStyle.SHORT)
           .optionalEnd()
-          .optionalStart()
-          .appendLiteral('Z')
-          .optionalEnd()
           .toFormatter()
           .withZone(ZoneOffset.UTC);