I have made this simple workaround using jquery-ui-timepicker-addon.js.
Simply put the following code in the question field of a brief-text question (remember that you have to
enable javascript in your survey)
Time question
<style>
.ui-timepicker-div .ui-widget-header { margin-bottom: 8px; }
.ui-timepicker-div dl { text-align: left; }
.ui-widget-header { display:none; }
.ui-datepicker-current { display:none; }
.ui-timepicker-div dl dt { height: 25px; margin-bottom: -25px; }
.ui-timepicker-div dl dd { margin: 0 10px 10px 65px; }
.ui-timepicker-div td { font-size: 90%; }
.ui-tpicker-grid-label { background: none; border: none; margin: 0; padding: 0; }
</style>
<script src="http://trentrichardson.com/examples/timepicker/jquery-ui-timepicker-addon.js"></script>
<script>
$(document).ready(function(){
$('#answer{SGQ}').timepicker({
timeText: 'Time',
hourText: 'hour',
minuteText: 'minute',
closeText: 'Done'
});
$('#answer{SGQ}').attr('readonly', 'readonly');
});
</script>