jira_time_calc.user.js

// ==UserScript==
// @match http://jira.fanhattan.com/*
// @match https://jira.fanhattan.com/*
// ==/UserScript==


var li = document.createElement("li");
var label = document.createElement("li");
document.querySelector(".aui-nav").appendChild(li);
document.querySelector(".aui-nav").appendChild(label);

var make_button = function(text, class_name){
  var button_a = document.createElement("a");
  button_a.appendChild(document.createTextNode(text));
  button_a.classList.add("aui-button")
  button_a.classList.add("aui-style")
  button_a.onclick = function(){
      var safe = function(x, d) { if(typeof d == "undefined") { d = 0.0} return isFinite(x) ? x : d };
      var t = {"day": 1, "days": 1, "hour": 0.125, "hours": 0.125, "week": 5, "weeks": 5}; 
      var sum = function(q){  return q.reduce(function(a,b){return safe(a) + safe(b); }, 0) };
      var time = sum([].slice.call(document.querySelectorAll(class_name)).map(function(e){
          return sum(e.innerText.split(", ").map(function(x){
              return safe(x.split(" ")[0]) * t[x.split(" ")[1]]
          }));
      }))
      label.innerHTML = "<span style='padding-left: 10px;'>" + time + " days</span>";
  }
  return button_a;
  
};

li.appendChild(make_button("Orig. Time", ".nav.timeoriginalestimate"));
li.appendChild(make_button("Rem. Time", ".nav.timeestimate"));