diff --git a/src/messages/messages.controller.ts b/src/messages/messages.controller.ts
index 90cf02a..9308ee6 100644
--- a/src/messages/messages.controller.ts
+++ b/src/messages/messages.controller.ts
@@ -226,7 +226,7 @@ export class MessagesController {
       const readEvent = {
         conversationId,
         readBy: userId,
-        readAt: new Date(),
+        readAt: new Date().toISOString(),
       };
       this.messagesGateway.sendToUser(otherUserId, 'messages_read', readEvent);
     }
diff --git a/src/messages/messages.gateway.ts b/src/messages/messages.gateway.ts
index 9d65096..28baf4b 100644
--- a/src/messages/messages.gateway.ts
+++ b/src/messages/messages.gateway.ts
@@ -140,7 +140,7 @@ export class MessagesGateway implements OnGatewayConnection, OnGatewayDisconnect
           const deliveredEvent = {
             messageIds: result.messageIds,
             conversationId: result.conversationId,
-            deliveredAt: result.deliveredAt,
+            deliveredAt: result.deliveredAt.toISOString(),
           };
           this.sendToUser(result.senderId, 'message_delivered', deliveredEvent);
         }
@@ -228,7 +228,7 @@ export class MessagesGateway implements OnGatewayConnection, OnGatewayDisconnect
     }
 
     try {
-      const message = await this.messagesService.createMessage(
+      let message = await this.messagesService.createMessage(
         data.conversationId,
         client.userId,
         data.message,
@@ -246,13 +246,17 @@ export class MessagesGateway implements OnGatewayConnection, OnGatewayDisconnect
 
           // Auto-mark as DELIVERED if recipient is online
           if (this.isUserOnline(otherUserId)) {
+            const deliveredAt = new Date().toISOString();
             await this.messagesService.markMessageDelivered(message.id);
+            // Update message object so sender gets correct status in callback
+            message = { ...message, status: 'DELIVERED' as any, deliveredAt } as any;
+
             const deliveredEvent = {
               messageId: message.id,
               conversationId: data.conversationId,
-              deliveredAt: new Date(),
+              deliveredAt,
             };
-            // Notify sender that message was delivered
+            // Also send event for clients that might have the old status cached
             this.sendToUser(client.userId, 'message_delivered', deliveredEvent);
           }
         }
@@ -327,7 +331,7 @@ export class MessagesGateway implements OnGatewayConnection, OnGatewayDisconnect
       const readEvent = {
         conversationId: data.conversationId,
         readBy: client.userId,
-        readAt: new Date(),
+        readAt: new Date().toISOString(),
       };
 
       // Notify via room (for clients viewing this conversation)