Sort ion-list by date

Question

Good morning, I am studying IONIC with Firebase and created a simple list where I want it to be sorted by update date. In the image we can see that the date is the same as it came from Firebase.

I tried to do it this way:

pedidos:any

constructor(){
    // Initialize Firebase
  const config = {
    apiKey: "c",
    authDomain: "c",
    databaseURL: "c",
    projectId: "c",
    storageBucket: "c.c.c",
    messagingSenderId: "c"
  };
  firebase.initializeApp(config);
  this.pedidos = new Array();

  let ref = firebase.database().ref('statuspedido').orderByChild('dataAtualizacao');//statuspedido
 ref.on('value', (dataSnapshot) =>{
     let items = dataSnapshot.val();
     for(let dados in items){
        this.pedidos.push(
            new PedidoModel(
                items[dados].idPedido,
                items[dados].dataEmissao,
                items[dados].dataAtualizacao,
                items[dados].vendedor,
                items[dados].frete,
                items[dados].transportadora,
                items[dados].status)
        )
     }
  })
}

and at firebase: