Detect what HTML5 features your browser can support using Modernizr and decide which missing features need to be back filled.
<script src="js/vendor/js-webshim/minified/polyfiller.js"></script>
<script>
if (Modernizr.inputtypes.date && Modernizr.inputtypes.number) {
// Do nothing
} else {
$.webshims.polyfill();
}
</script>