Take the coursera lectures' running times and sum them up for each week.

coursera-week-sums.js

[].forEach.call(
  $('.course-item-list-header'),
  function(el){
    var secSum = 0,
        minSum = 0,
        hourSum = 0
        originalTitle = '';
    originalTitle = $(el).find('h3').text();
    //console.log( $(el).find('h3').text() );
    [].forEach.call( $(el).next().find('.lecture-link'),
    function(subEl){
      secSum += parseInt($(subEl).text().match(/\:(\d+)\)/)[1], 10);
      minSum += parseInt($(subEl).text().match(/(\d+)\:/)[1], 10);
    });
    //console.log('hoursum : ' + hourSum + ', minSum: ' + minSum + ', secSum: ' + secSum);
    minSum += secSum / 60;
    secSum = secSum % 60;
    hourSum = minSum / 60;
    minSum = minSum % 60;
    $(el).find('h3').append(' (' + parseInt(hourSum, 10) + ':' + parseInt(minSum, 10) + ':' + parseInt(secSum, 10) + ')');
  }
);