New Twiddle

controllers.application\.js

import Controller from '@ember/controller';
import { inject as service } from '@ember/service';
import { tracked } from '@glimmer/tracking';
import { next } from '@ember/runloop';
const createdAt = new Date().toUTCString();

let inc = 0;

export default class ApplicationController extends Controller {
  @service store;

  constructor() {
    super(...arguments);
    this.appNameRenderCount = 0;
    this.createdAtRenderCount = 0;
  }

  model = this.store.push({
    data: {
      type: 'app',
      id: '1',
      attributes: {
        createdAt: new Date(createdAt),
        appName: 'Test App'
      }
    }
  });

  get appName() {
    next(() => this.incrementProperty('appNameRenderCount'));
    return this.model.appName;
  }

  get createdAt() {
    next(() => this.incrementProperty('createdAtRenderCount'));
    console.log(this.model.createdAt);
    return this.model.createdAt.toString();
  }
	
  updateRecord = () => {
    window.dates = window.dates || [this.model.createdAt];
    
    debugger;
    this.store.push({
      data: {
        type: 'app',
        id: '1',
        attributes: {
          createdAt: new Date(createdAt),
          appName: 'Test App' // 'Test App:' + inc++
        }
       }
    });
    
    window.dates.push(this.model.createdAt);
    console.log(window.dates);
  }
}

models.app\.js

import Model from 'ember-data/model';

import attr from 'ember-data/attr';

export default class extends Model {
  @attr('date') createdAt;
  @attr('string') appName;
}

templates.application\.hbs

<h1>Welcome to {{this.appName}}</h1>
<br>
CreatedAt: {{this.createdAt}}<br>
AppName Renders: {{this.appNameRenderCount}}<br>
CreatedAt Renders: {{this.createdAtRenderCount}}<hr>
<button {{on "click" this.updateRecord}}>Refresh</button>
<br>
{{outlet}}
<br>
<br>

twiddle\.json

{
  "version": "0.17.1",
  "EmberENV": {
    "FEATURES": {},
    "_TEMPLATE_ONLY_GLIMMER_COMPONENTS": false,
    "_APPLICATION_TEMPLATE_WRAPPER": true,
    "_JQUERY_INTEGRATION": true
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.5.1/jquery.js",
    "ember": "3.18.1",
    "ember-template-compiler": "3.18.1",
    "ember-testing": "3.18.1"
  },
  "addons": {
    "@glimmer/component": "1.0.0",
    "ember-data": "3.18.0"
  }
}