<label for="appt-time">Choose an appointment time0: </label>
<input id="appt-time" type="time" name="appt-time" value="00:00">
<!DOCTYPE html>
<html>
<head>
<style>
input {
padding: 10px;
}
</style>
</head>
<body>
<h1>Example</h1>
<form action="/form/submit" method="post">
<input type="week" name="week" min="2018-W1" max="2018-W52">
</form>
</body>
</html>
<form>
<label for="appt-time">Choose an appointment time: </label>
<input id="appt-time" type="time" name="appt-time" step="2">
</form>
<label for="appt-time">Choose an appointment time0: </label>
<input id="appt-time" type="time" name="appt-time" value="00:00">