backend/views/parser/checkPrice.php

<?php
use yii\helpers\Html;
use yii\grid\GridView;
use yii\grid\SerialColumn;
use yii\grid\DataColumn;
/* @var $this yii\web\View */
/* @var $searchModel backend\models\CatalogSearch */
/* @var $dataProvider yii\data\ActiveDataProvider */
$this->title = 'Проверка прайсов';
$this->params['breadcrumbs'][] = $this->title;
?>
<div class="catalog-index">
    <h1><?= Html::encode($this->title) ?></h1>
    <?= GridView::widget( ['dataProvider' => $dataProvider,
        'columns' => [['class' => SerialColumn::className()],
            [
                'label' =>'Поставщик',
                'value' => function ($data) {
                    return '№ ' .$data->id . ' ' . $data->name;
                },
            ],
                           ['label' =>'Дата обновления',
                           'attribute' => 'price_date_update' ],
        ['label' => 'Кол-во дней',
            'value' => function ($data) {
                $date1 = new DateTime("now");
                $date2 = new DateTime( $data->price_date_update );
                $quo_days = $date2->diff($date1)->format('%R%a');
                // уберем первый символ - там знак "+"
                $quo_days = substr( $quo_days, 1, strlen($quo_days) );
                $quo_days = (int) $quo_days;
                
                if($quo_days > 15)
                    $quo_days = '>15';
                return $quo_days;
            }
        ]
        ]] );?>
</div>