old_contents: var Models = {};
  Models.ItemListing = Backbone.Model.extend({
  	defaults: {
  		id: '',
  		name: '',
  		price: '',
  		location: '',
  		buyers: [],
  		owner: '',
  		imageUrl: ''
  	},
  	initialize: function() {
  
  	}
  });
  
  Models.ItemListings = Backbone.Collection.extend({
  	model: Models.ItemListing
  });
new_contents: var Models = {};
  Models.ItemListing = Backbone.Model.extend({
  	defaults: {
  		id: '',
  		name: '',
  		price: '',
  		location: '',
  		buyers: [],
  		owner: '',
  		imageUrl: '',
  		dateStart: '',
  		dateExpire: ''
  	},
  	initialize: function() {
  
  	}
  });
  
  Models.ItemListings = Backbone.Collection.extend({
  	model: Models.ItemListing
  });
subject: Add start and end date to model.