dateFormat: 'php:' do not work correct

[ComradePashka]

With simple config

// config:
'formatter' => [
  'class' => 'yii\i18n\Formatter',
//  'dateFormat' => 'php:d-M-Y',
  'dateFormat' => 'dd.MM.yyyy',
],

// model rules():
['published_at', 'date', 'timestampAttribute' => 'published_at'],

// widget:
$form->field($model, 'published_at')->widget(DatePicker::className(), [
  'options' => ['class' => 'form-control'],
])

everything works ok, but if 'dateFormat' of formatter will be changed to, for example 'php:d-M-Y' datePicker widget starts handle different with DateValidator formatting, so posted value will never pass validation.

if alternately set up 'format' for model rule and same format as 'dataFormat' for DatePicker widget to avoid using global formatter values, anyways it will handle format 'php:d-M-Y' incorrectly. Client script looks like:

  $('#post-published_at').datepicker($.extend({}, $.datepicker.regional['ru'], {"dateFormat":"dd-M-yy"}));

and when form with existent data loads, then data shown (for russian locale) as "19-мая-2016" but when I changed date - it shown as "18-Май-2016". so it has different form of nouns for month and obviously format is not same.

I am not sure it is real bug, but looks like some date format won't be handled correctly as described.

Additional info

component	version
Yii vesion	2.0.8
PHP version	7.0.4
Operating system	Ubuntu xenial

[cebe]

PHP can not handle international date format. you have to use the intl format for that.

[ComradePashka]

ah. ok, maybe it is good idea to make small reminding note about it in documentation?