Total number of hours watched on Netflix

gistfile1.js

var timings = document.querySelectorAll("#rhtable tr > td:nth-of-type(4)");
var totalHours = 0;
for (var i = 0; i < timings.length; i++) {
  var timing = timings[i].innerHTML.split(":");
  totalHours += parseFloat(timing[0]) + (parseFloat(timing[1]) / 60) + (parseFloat(timing[1]) / 3600);
}
alert("Hours watched: " + totalHours);

Visit https://ca.netflix.com/WiViewingActivity?all=true to use the script above as a bookmarklet.