Простая форма определения выбранного значения в Radio Button:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>jQuery Check/Uncheck Radio Button</title>
<script src="https://code.jquery.com/jquery-1.12.4.min.js"></script>
<script type="text/javascript">
$(document).ready(function(){
myFunc.call();
$(".intervalcheck").change(function(){
myFunc.call();
});
});
function myFunc(){
var intervalCheck = $("input[name='intervalname']:checked").val();
$("#test" ).empty();
$("#test" ).append(intervalCheck);
}
</script>
</head>
<body>
<p class="intervalcheck">
<label><input type="radio" name="intervalname" value="7d">7d</label>
<label><input type="radio" name="intervalname" value="3d">3d</label>
<label><input type="radio" name="intervalname" value="1d" checked>1d</label>
<label><input type="radio" name="intervalname" value="12h">12h</label>
<label><input type="radio" name="intervalname" value="6h">6h</label>
<label><input type="radio" name="intervalname" value="4h">4h</label>
<label><input type="radio" name="intervalname" value="1h">1h</label>
<label><input type="radio" name="intervalname" value="15min">15min</label>
</p>
</body>
<div id='test'>sdfdafdf</div>
</html>