datetimepicker-kv.css

/*!
 * @copyright Copyright &copy; Kartik Visweswaran, Krajee.com, 2014 - 2017
 * @package yii2-widgets
 * @subpackage yii2-widget-datepicker
 * @version 1.4.4
 *
 * Custom styling for DateTimepicker
 * Built for Yii Framework 2.0
 * Author: Kartik Visweswaran
 * Year: 2014
 * For more Yii related demos visit http://demos.krajee.com
 */
.input-group.date.disabled  .input-group-addon .glyphicon {
    cursor: not-allowed;
    filter: alpha(opacity=65);
    -webkit-box-shadow: none;
    box-shadow: none;
    opacity: .65;
}