discourse-custom-wizard/assets/javascripts/wizard/components/wizard-field-date.js.es6

import Component from "@ember/component";
import { observes } from 'discourse-common/utils/decorators';

export default Component.extend({
  @observes('date')
  setValue() {
    this.set('field.value', this.date.format(this.field.format));
  },
  
  actions: {
    onChange(value) {
      this.set('date', moment(value));
    }
  }
});