Пропадает дата из datefield после сохранения

{
    xtype: 'datefield'
    ,fieldLabel: _('project_dob')
    ,description: '<b>[[*dob]]</b><br />'+_('project_dob_help')
    ,format: MODx.config.manager_date_format
    ,id:'dob'
    ,name: 'dob'
    ,allowBlank: false
    ,anchor: '50%'
    ,value: config.record.dob || ''
}

class ProjectUpdateManagerController extends ResourceUpdateManagerController {
	public function prepareResource() {
		$this->resourceArray['dob'] = strftime(%m/%d/%Y, $this->resourceArray['dob']);
	} 
}