issue in laravel php artisan server [closed]

I have installed a live laravel project on my localhost. when I run there are two warning errors that occur.

Anyone have idea how to fix it

Warning: The use statement with the non-compound name 'DateTime' has no effect in app\helper.php on line 22

Warning: The use statement with the non-compound name 'DateTimeZone' has no effect i
n \app\helper.php on line 23

via Chebli Mohamed