Product Options javascript file linked from: https://support.boldcommerce.com/hc/en-us/articles/210645923-Product-Options-Date-Picker
<link href="//secure.shappify.com/apps/options/glDatePicker/styles/glDatePicker.default.css" rel="stylesheet" type="text/css">
<script type="text/javascript" src="https://secure.shappify.com/apps/options/glDatePicker/glDatePicker.js"></script>
<script>
function shappify_options_rendered()
{
jQuery('input[name*="Date"],input[name*="date"]').glDatePicker();
/* Fixes conditional logic giving date picker wrong position on the page*/
$(document).on('focus','.gldp-el', function(){
var dp = jQuery(this).glDatePicker(true);
dp.render();
var glp_id = $(this).attr('gldp-id');
var height = $(this).outerHeight();
var width = $(this).outerWidth();
var offset = $(this).offset();
$('div[gldp-el="'+glp_id+'"]').css({
top: offset.top+height+'px',
width: width+'px'
});
});
jQuery('[name*="Date"], [name*="date"]').prop('readonly', true);
};
</script>