Timepicker.js is a project mainly written in JavaScript, it's free.
timepicker by Sam Collet and Anders Fajerson extended to handle refreshing position
/*
A time picker for jQuery
Based on original timePicker by Sam Collet (http://www.texotela.co.uk) -
copyright (c) 2006 Sam Collett (http://www.texotela.co.uk)
Based on extended timePicker by Anders Fajerson
Copyright (c) 2009 Anders Fajerson (http://perifer.se)
Dual licensed under the MIT and GPL licenses.
Copyright (c) 2010 Scott Motte
@name timePicker
@version 0.3
@author Scott Motte (http://spitfiresky.com)
@example $("#mytime").timePicker();
@example $("#mytime").timePicker({step:30, startTime:"15:00", endTime:"18:00"});
@example if you need to refresh it's position just call $("#mytime").timePicker('refreshPosition'); */