add_filter( 'aioseo_local_business_output_opening_hours_instance', 'aioseo_change_local_business_output_opening_hours_instance', 10, 3 );

function aioseo_change_local_business_output_opening_hours_instance( $instance, $postId, $openingHoursData ) {

	$instance['showSunday'] = false;

	return $instance;

}