For some forms you want display the days from future/past days and other days need to disabled, then this scenario will help.
<?php
use yii\jui\DatePicker;
use yii\widgets\ActiveForm;
?>
<?php $form = ActiveForm::begin(['id' => 'profile-form']); ?>
.....
<?php
$day = '+5d'; //if you want to display +5 days from current date means for future days.
#(or)
$day = '-5d'; //if you want to display -5 days from current date means older days.
?>
<?= $form->field($model, 'date_of_birth')->widget(DatePicker::classname(), ['dateFormat' => 'php:M d, Y', 'options' => ['readonly' => true], 'clientOptions' => [ 'changeMonth' => true, 'changeYear' => true, 'yearRange' => '1980:'.date('Y'), 'maxDate' => $day]]) ?>
.....
<?php ActiveForm::end(); ?>