We have a date field on an item in Sitecore (version 8.1 Update 3). When that field is rendered in the Content Editor, the correct date formatting is used (US, in our case: `MM/DD/YYYY`):

[![Date picker in Content Editor](https://i.stack.imgur.com/4FBVA.png)](https://i.stack.imgur.com/4FBVA.png)

However, when that page is loaded in the Experience Editor, the date picker displays the wrong format (`DD/MM/YYYY`):

[![Date picker in Experience Editor](https://i.stack.imgur.com/aNPb1.png)](https://i.stack.imgur.com/aNPb1.png)

Does anyone know how to make the Experience Editor date picker show the proper format?

I've already reviewed [a similar-looking question](https://sitecore.stackexchange.com/questions/11553/sitecore-9-0-1-datepicker-displaying-wrong-format), but our `DatePicker.js` already had the updated code, so that's not the issue.