Date placeholder not appearing

Hello, and thanks in advance for any help. So i have added a placeholder for the date field however the placeholder is not appearing on the field, instead the DD/MM/YYYY appears. A live link to my project is here: bib.vergedesign.co.uk

the code that i am using is here :

<div class="row text-center">

<div class="col-xs-6">
<label>[text* first-name placeholder "First Name*"] </label></div>

<div class="col-xs-6">
<label>[text* last-name placeholder "Last Name*"] </label></div>

<div class="col-xs-6">
<label>[text* postcode placeholder "Postcode*"] </label></div>

<div class="col-xs-6">
<label>[date* dob min:1960-01-01 placeholder "Date of Birth*"] </label></div>

<div class="col-sm-12">
<label>[email* your-email placeholder "Your email *"] </label></div>

<div class="col-sm-12">
[submit "Send"]
</div>
</div>
</div>