<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<link rel="stylesheet" type="text/css" href="css/bootstrap.css">
<link rel="stylesheet" type="text/css" href="css/bootstrap-theme.css">
<link rel="stylesheet" type="text/css" href="css/style.css">
<script type="text/javascript" src="js/jquery-3.3.1.js"></script>
<script type="text/javascript" src="js/bootstrap.js"></script>
</head>
<body>
<div>
<input type="date" class="datepicker" data-date-format="dd-mm-yy" id="date" name="date" placeholder="Дата" required>
</div>
</body>
</html>
chrome по прежнему показывает свой формат
dd/mm/yyyy