ate('27 Feb 2012').getTime(),
            new Date('27 Feb 2013').getTime()
          )
        })
      
      document.querySelector('#ytd').addEventListener('click', function(e) {
        resetCssClasses(e)
      
        chart.zoomX(
          new Date('01 Jan 2013').getTime(),
          new Date('27 Feb 2013').getTime()
        )
      })
      
      document.querySelector('#all').addEventListener('click', function(e) {
        resetCssClasses(e)
      
        chart.zoomX(
          new Date('23 Jan 