[REQUIRED] Step 2: Describe your environment

• Operating System version: Windows 11
• Firebase SDK version: 2.3.0
• Firebase Product: Messaging
• .NET version: 6
• OS: Windows

[REQUIRED] Step 3: Describe the problem

Steps to reproduce:

What happened? How can we make the problem occur?
This could be a description, log/console output, etc.

I am trying to send notification messages from my backend to the phones, which is working perfectly if I just use the "Notification" in the "Message" class. However when I try to use an AndroidNotification i get the following error:
FirebaseAdmin.Messaging.FirebaseMessagingException: Invalid value at 'message.android.notification.event_time' (type.googleapis.com/google.protobuf.Timestamp), Field 'event_time', Invalid time format: Failed to parse input

Relevant Code:

Message message = new Message() { Android = new AndroidConfig() { Notification = new AndroidNotification() { Title = "Test title", Body = "Body test", TitleLocKey = "added_to_project", BodyLocKey = "project", EventTimestamp = new DateTime(2011, 6, 10), }, Priority = 0, }, Data = new Dictionary<string, string>() { {"type", "1"}, }, Token = deviceToken, };