     {id} = @props
 
     periodTasking = @getSavedTaskingFor(period.id)
+    {taskingOpensAt, taskingDueAt} = @getDefaultPlanDates(period.id)
 
     if ev.target.checked
-      TaskPlanActions.enableTasking(@props.id, period.id,
-        periodTasking.opens_at, periodTasking.due_at
-      )
+      if periodTasking?
+        TaskPlanActions.enableTasking(@props.id, period.id,
+          periodTasking.opens_at, periodTasking.due_at
+        )
+      else
+        {taskingOpensAt, taskingDueAt} = @getDefaultPlanDates(period.id)
+        TaskPlanActions.enableTasking(@props.id, period.id,
+          taskingOpensAt, taskingDueAt
+        )
     else
       TaskPlanActions.disableTasking(@props.id, period.id)
 

      @setState({showingPeriods: not (commonDates and hasAllTaskings), savedTaskings: periods})
      TaskPlanActions.disableEmptyTaskings(planId)

  # this will be called whenever the course store loads, but won't if
  # the store has already finished loading by the time the component mounts
  bindUpdate: ->

    </BS.Row>

  renderEnabledTasking: (plan) ->
    {taskingOpensAt, taskingDueAt} = @getDefaultPlanDates(plan.id)

    <BS.Row key={plan.id} className="tasking-plan tutor-date-input">
      <BS.Col sm=4 md=3>
        <input
          id={"period-toggle-#{plan.id}"}
