trying to get rid of time offset in message list

Signed-off-by: Stephan Richter <s.richter@srsoftware.de>

messages/src/main/java/de/srsoftware/umbrella/message/MessageSystem.java

@@ -39,6 +39,7 @@ import jakarta.mail.internet.MimeMessage;
 import jakarta.mail.internet.MimeMultipart;
 import jakarta.mail.util.ByteArrayDataSource;
 import java.io.IOException;
+import java.time.ZoneId;
 import java.util.*;
 import org.json.JSONArray;
 import org.json.JSONObject;
@@ -328,7 +329,7 @@ public class MessageSystem extends BaseHandler implements PostBox, EventListener
 
 		var sender  = message.sender().name();
 		var subject = message.subject();
-		var time    = envelope.time().format(TIME_FORMATTER);
+		var time    = envelope.time().atZone(ZoneId.systemDefault()).format(TIME_FORMATTER);
 		var id      = envelope.id();
 		return new JSONObject(Map.of(SENDER,sender,SUBJECT,subject,TIMESTAMP,time,ID,id));
 	}