Online PHP editor | refs for jK1NU

<?php $_GET['week_of']=20151111; if(!isset($_GET['week_of'][8])&&ctype_digit($_GET['week_of'])&& (DateTime::createFromFormat('Ymd',$_GET['week_of'])->format('N')===1) ){ $week_of=DateTime::createFromFormat('Ymd',$_GET['week_of'])->format('Y-m-d'); }elseif(((new DateTime())->format('N'))==1){ $week_of=new DateTime('this monday'); }else{ $week_of=new DateTime('last monday'); } echo $week_of;