<input type="date" />
has really bad cross browser support. In my experience, some browsers use different date formats altogether.
I'd really recommend using jQuery UI's Datepicker for this which will give you control over what format is inputted. If you include:
<link rel="stylesheet" href="https://ajax.googleapis.com/ajax/libs/jqueryui/1.11.4/themes/smoothness/jquery-ui.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.3/jquery.min.js"></script>
<script src="https://ajax.googleapis.com/ajax/libs/jqueryui/1.11.4/jquery-ui.min.js"></script>
And use:
$('.datepicker').datepicker({ dateFormat: 'mm/dd/yy' }).val();
Naming any input types with a class="datepicker"
parameter, this should work.
This should display a good datepicker that will input the date in the format you want. You may need to use some regex to ensure the correct format gets sent to the server, however.