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        timeFormat: 'HH:mm',
        // year, month, day and seconds are not important
        minTime: new Date(0, 0, 0, 8, 0, 0),
        maxTime: new Date(0, 0, 0, 15, 0, 0),
        // time entries start being generated at 6AM but the plugin 
        // shows only those within the [minTime, maxTime] interval
        startHour: 6,
        // the value of the first item in the dropdown, when the input
        // field is empty. This overrides the startHour and startMinute 
        // options
        startTime: new Date(0, 0, 0, 8, 20, 0),
        // items in the dropdown are separated by at interval minutes
        interval: 10
    $('input.change-format').click(function() {
        // change timeFormat option here
        $('input.timepicker').data('TimePicker').options.timeFormat = 'HH:mm:ss p';
        // since v1.1.2 does not support changing most of the options, we need
        // to trick the plugin into thinking the next time the dropdown needs
        // to be displayed is the first time, so it re-generates the items, 
        // using the new format
        $('input.timepicker').data('TimePicker').items = null;
        $('input.timepicker').data('TimePicker').widget.instance = null;

<h1>jQuery TimePicker Demo</h1>

<p>The dropdown starts using <code>HH:mm</code> as the timeFormat. Click the input field to see it.<p/>
    <p>As of version 1.1.2 most of the options can't be easily changed, but it's possible. Pressing the button will change the timeFormat option to <code>HH:mm:ss p</code>. The function associated to the button's click event shows how it was done.</p>

<input class="timepicker" name="timepicker" /><input class="change-format" type="button" value="Change timeFormat option">

<a href="http://github.com/you"><img style="position: absolute; top: 0; right: 0; border: 0;" src="https://s3.amazonaws.com/github/ribbons/forkme_right_red_aa0000.png" alt="Fork me on GitHub"></a>
body {
    background: #EFEFEF;
    padding: 20px;
h1 {
    font-weight: bold;
    margin-top: 50px;
p {
    margin: 10px 0;

External resources loaded into this fiddle: