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<?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->format('D Y-m-d');

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