Display a clock in the user bar

Question

Screenshot

About

This user script adds a clock on the user bar next to the search box. When visiting a Stack Exchange site I sometimes like to know the current Stack Exchange time. This clock calculates the time locally so it isn't "server time" but it is close enough for me.

The clock display is formatted as a link to the "current time" query on Wolfram Alpha so that it's styled the same as the other items on the user bar.

It should work on any site in the Stack Exchange network, except for the network hub site at stackexchange.com which uses a different template.

License

Released into the public domain.

Script

Install

// ==UserScript==
// @name           Stack Exchange Clock
// @namespace      http://stackexchange.com/
// @description    Display UTC clock on Stack Exchange sites.
// @include        http://stackoverflow.com/*
// @include        http://serverfault.com/*
// @include        http://superuser.com/*
// @include        http://stackapps.com/*
// @include        http://askubuntu.com/*
// @include        http://answers.onstartups.com/*
// @include        http://*.stackexchange.com/*
// @include        http://*.stackoverflow.com/*
// @include        http://*.serverfault.com/*
// @include        http://*.superuser.com/*
// @include        http://*.askubuntu.com/*
// @include        http://*.answers.onstartups.com/*
// ==/UserScript==

/* Generate the current time string in UTC. */
function get_time() {
    var today = new Date();
    var h = today.getUTCHours();
    var m = zero_pad(today.getUTCMinutes());
    var s = zero_pad(today.getUTCSeconds());

    return h + ":" + m + ":" + s + " UTC";
}

/* Add a leading zero if required. */
function zero_pad(number) {
    if (number >= 0 && number < 10) {
        return "0" + number;
    }
    return number;
}

/* Update the time display. */
function update_time() {
    var stamp = document.getElementById('utc-clock');
    stamp.innerHTML = get_time();
}

/* Generate the HTML element for the stamp and insert,
   wrap time in a link to fit in with the footer menu. */
var time_url = "http://www.wolframalpha.com/input/?i=current%20time";
var time_block = document.createElement("span");
var inner_s = "<span class='lsep'>|</span> ";
inner_s += "<a id='utc-clock' title='Current Time' href='";
inner_s += time_url + "'>" + get_time() + "</a>";
time_block.innerHTML = inner_s;

var target = document.getElementById('hlinks-custom');
if (target) {
    target.parentNode.insertBefore(time_block, target.firstSibling);
}

var f = function() { update_time(); }
window.setInterval(f, 1000);