Open quiz based on scheduled date and time in laravel

your best bet is to use UTC as your default timezone... Wiki Weather forecasts and maps all use UTC to avoid confusion about time zones and daylight saving time. ... This ensures that all pilots, regardless of location, are using the same 24-hour clock..

Or if you want you could get each visitors' localtime and adjust it accordingly.

--Helper function...
if(! function_exists('getVisitorsLocalTime')) {
        function getVisitorsLocalTime(){
    
            $ip = file_get_contents("http://ipecho.net/plain");
            $url = 'http://ip-api.com/json/'.$ip;
            $tz = file_get_contents($url);

            return  json_decode($tz,true)['timezone'];
        }
 }

now you can use the above helper function to get each visitor's local time and compare it with your quizez open time and adjust accordingly...

 //time based on Visitor/User of your website's timezone
Carbon::now(getVisitorsLocalTime());

//time based on your application's timezone
Carbon::now()