User script: Add a select list to WordPress edit pages to make it easy to set a publication date in the past

manifest.json

{
   "manifest_version": 2,
   "content_scripts": [ {
      "exclude_globs": [  ],
      "include_globs": [ "BLOG_URL/wp-admin/post*" ],
      "js": [ "script.js" ],
      "matches": [ "http://*/*", "https://*/*" ],
      "run_at": "document_idle"
   } ],
   "converted_from_user_script": true,
   "description": "Add a select list to WordPress edit pages to make it easy to set a publication date in the past",
   "key": "Ilesh6T+3DJiNzNbQXBGjKp0J9uU8sLBwA+kAMEzyRI=",
   "name": "WordPress Quick Pick",
   "version": "1.0"
}

script.js

// ==UserScript==
// @name           WordPress Quick Pick
// @namespace      http://thunderguy.com/
// @description    Add a select list to WordPress edit pages to make it easy to set a publication date in the past
// @author         Bennett McElwee, bennett@thunderguy.com
// ==/UserScript==

// Chrome-compatible script injection: http://stackoverflow.com/a/8890387/61754
var main = function () {

(function($) {

var dayNames = ["Sun","Mon","Tue","Wed","Thu","Fri","Sat"];
var monthNames = ["Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec"];

$(".edit-timestamp").after("<div><select class='day-picker'><option>Quick pick...</option></select></div>");
var sysTime = new Date().getTime();
for (var i = 0; i < 15; ++i) {
	var date = new Date(sysTime - i * 24 * 60 * 60 * 1000);
	var day   = date.getDate();
	var month = date.getMonth() + 1; if (month < 10) { month = "0" + month; }
	var year  = date.getFullYear();
	var text = dayNames[date.getDay()] + " " + day + " " + monthNames[date.getMonth()] + " " + year;
	if (i == 0) { text = text + " - today"; }
	else if (i == 1) { text = text + " - yesterday"; }
	$(".day-picker").append("<option value='"+year+"-"+month+"-"+day+"'>"+text+"</option>")
}
$(".day-picker").change(function() {
	var date = $(this).val().split("-");
	$("#aa").val(date[0]);
	$("#mm").val(date[1]);
	$("#jj").val(date[2]);
	$(this).val("");
	$(".save-timestamp").click();
});

})(window.jQuery);

};

// Inject the main script
var script = document.createElement("script");
script.textContent = "(" + main.toString() + ")();";
document.body.appendChild(script);