JSFiddle - React, Tailwind, and code Playground

HTML

<div ng-controller="myCtrl">
{{sameDay(posts[0].created,posts[1].created)}}
</div>

JavaScript

function myCtrl($scope){
    $scope.posts = [{"content":"content1",
          "created":"2016-12-27T14: 15: 27.747Z"},
         {"content":"content2",
          "created":"2013-12-27T14: 15: 02.956Z"}];
    
    $scope.sameDay = function(date1,date2){
        return date1.substring(0,10) === date2.substring(0,10);
    }
}