   mixins: [CellStatusMixin] # prop validation
 
   render: ->
-    pieValue = Math.round((@props.task.correct_exercise_count / @props.task.exercise_count) * 100)
+    pieValue =
+      Math.round((@props.task.correct_exercise_count / @props.task.exercise_count) * 100)
+    tooltip =
+      <BS.Tooltip>
+        <div>Date Last Worked: <Time format='MMM. D' date={@props.task.last_worked_at} /></div>
+      </BS.Tooltip>
+
     <div className="cc-cell">
       <Router.Link className="score" to='viewTaskStep'
         data-assignment-type="#{@props.task.type}"

React  = require 'react'
Router = require 'react-router'

Time = require '../time'
CellStatusMixin = require './cell-status-mixin'

            "#{pieValue}%"
        }
      </Router.Link>
      <BS.OverlayTrigger
        placement='top'
        delayShow={1000}
        delayHide={0}
        overlay={tooltip}>
        <div className="worked">
          <PieProgress size={25} value={pieValue} />
        </div>
      </BS.OverlayTrigger>
    </div>


