Laravel task scheduler not working for specified time range

I have a Laravel 5 task which I am scheduling to run between a specified time range every day:

protected function schedule(Schedule $schedule)
    {
         $schedule->call(function () {

             $pending_bookings = Booking::draft()->get();

             foreach($pending_bookings as $booking) {
                 if(!$booking) abort(404);
                 $booking->notify(new sendReminder($booking));
             }

        })->daily()->timezone('Europe/London')->between('14:00', '15:00');
    }

This does not work, however if I change it to run every minute using everyMinute(); then it does run successfully:

       $schedule->call(function () {

             // send reminder SMS for all pending bookings
             $pending_bookings = Booking::draft()->get();

             foreach($pending_bookings as $booking) {
                 if(!$booking) abort(404);
                 $booking->notify(new sendReminder($booking));
             }

        })->everyMinute();

My CRON on the server is set to run every half an hour as it's a shared hosting so it can't run for less than half an hour:

0,30    *   *   *   *   /usr/local/bin/php -q /home/username/public_html/bookings/artisan schedule:run >> /dev/null 2>&1

Anyone know why the first cron job: daily()->timezone('Europe/London')->between('14:00', '15:00'); is not running?

via Chebli Mohamed