{"action":"created","issue":{"url":"https://api.github.com/repos/callemall/material-ui/issues/4052","repository_url":"https://api.github.com/repos/callemall/material-ui","labels_url":"https://api.github.com/repos/callemall/material-ui/issues/4052/labels{/name}","comments_url":"https://api.github.com/repos/callemall/material-ui/issues/4052/comments","events_url":"https://api.github.com/repos/callemall/material-ui/issues/4052/events","html_url":"https://github.com/callemall/material-ui/issues/4052","id":149925648,"number":4052,"title":"[DatePicker] wrong week days when using `formatDate`","user":{"login":"luisrudge","id":941075,"avatar_url":"https://avatars.githubusercontent.com/u/941075?v=3","gravatar_id":"","url":"https://api.github.com/users/luisrudge","html_url":"https://github.com/luisrudge","followers_url":"https://api.github.com/users/luisrudge/followers","following_url":"https://api.github.com/users/luisrudge/following{/other_user}","gists_url":"https://api.github.com/users/luisrudge/gists{/gist_id}","starred_url":"https://api.github.com/users/luisrudge/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/luisrudge/subscriptions","organizations_url":"https://api.github.com/users/luisrudge/orgs","repos_url":"https://api.github.com/users/luisrudge/repos","events_url":"https://api.github.com/users/luisrudge/events{/privacy}","received_events_url":"https://api.github.com/users/luisrudge/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":11,"created_at":"2016-04-21T00:47:48Z","updated_at":"2016-04-21T19:59:50Z","closed_at":null,"body":"### With error:\r\n![image](https://cloud.githubusercontent.com/assets/941075/14694667/16a7210a-0741-11e6-9651-f534e3f93b71.png)\r\n\r\n```js\r\nconst dateTimeFormat = new Intl.DateTimeFormat('en-AU');\r\n<DatePicker DateTimeFormat={() => dateTimeFormat} formatDate={dateTimeFormat.format} locale=\"en-AU\" />\r\n```\r\n\r\n### Without error\r\n![image](https://cloud.githubusercontent.com/assets/941075/14694708/7e6eba14-0741-11e6-8960-aaa29a97fea0.png)\r\n\r\n`<DatePicker  />`\r\n\r\nI think the component is using the `formatDate` method everywhere and that's causing the error"},"comment":{"url":"https://api.github.com/repos/callemall/material-ui/issues/comments/213091369","html_url":"https://github.com/callemall/material-ui/issues/4052#issuecomment-213091369","issue_url":"https://api.github.com/repos/callemall/material-ui/issues/4052","id":213091369,"user":{"login":"luisrudge","id":941075,"avatar_url":"https://avatars.githubusercontent.com/u/941075?v=3","gravatar_id":"","url":"https://api.github.com/users/luisrudge","html_url":"https://github.com/luisrudge","followers_url":"https://api.github.com/users/luisrudge/followers","following_url":"https://api.github.com/users/luisrudge/following{/other_user}","gists_url":"https://api.github.com/users/luisrudge/gists{/gist_id}","starred_url":"https://api.github.com/users/luisrudge/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/luisrudge/subscriptions","organizations_url":"https://api.github.com/users/luisrudge/orgs","repos_url":"https://api.github.com/users/luisrudge/repos","events_url":"https://api.github.com/users/luisrudge/events{/privacy}","received_events_url":"https://api.github.com/users/luisrudge/received_events","type":"User","site_admin":false},"created_at":"2016-04-21T19:59:50Z","updated_at":"2016-04-21T19:59:50Z","body":"I think the issue is because I'm not passing the DateTimeFormat constructor, I'm passing the created object (`DateTimeFormat={() => aussieFormat}`).\r\n\r\nusing this works:\r\n\r\n```js\r\n    let DateTimeFormat;\r\n    if (areIntlLocalesSupported(['en-AU'])) {\r\n      DateTimeFormat = Intl.DateTimeFormat;\r\n    } else {\r\n      const IntlPolyfill = require('intl');\r\n      DateTimeFormat = IntlPolyfill.DateTimeFormat;\r\n      require('intl/locale-data/jsonp/en-AU');\r\n    }\r\n    <DatePicker DateTimeFormat={DateTimeFormat} locale=\"en-AU\" />\r\n```"}}