DetailView: minutes instead of month shown (datetime)


In on of my tables I have a column last_modified created as DATETIME. So one entry there e.g. is 2014-10-15 07:36:03.

Now I try to format the output, but is does not work as I would like to have it.

<?= DetailView::widget([

        'model' => $model,

        'attributes' => [




                'attribute' => 'last_modified',

                'format' => ['datetime', 'Y-m-d'],




    ]) ?>

The first output is 2014-10-15 07:36:03 as expected.

The second output is 2014-36-15 but I was expecting 2014-10-15.

I get the same output with

'format' => ['date', 'Y-m-d'],


For me it looks like there was shown year-minute-day but I would like to have the month instead. What do I not see here and how can I get my desired output?

Thanks in advance!

Best regards,