phpfiddle

1<form action="../../form-result.php" method="post" target="_blank">
2  <p>
3    Desired time to receive the call: <input type="time" name="desiredcalltime" list="calltimeslist">
4    <input type="submit" value="Send data">
5  </p>
6</form>
7<datalist id="calltimeslist">
8  <option value="16:00">
9  <option value="16:30">
10  <option value="17:00">
11  <option value="17:30">
12</datalist>
13