How to use ScheduleTask in a dynamic module? [duplicate]

Question

I have a little timer widget that times two separate tasks:

It is simple enough, but I can't see why it's not working. Am I not understanding the connection between ScheduleTasks and Dynamics?

Here is the code:

With[{maxLearning = 60, maxWriting = 60},
 DynamicModule[{learning = maxLearning, writing = maxWriting, lt, wt},
  lt = CreateScheduledTask[learning--];
  wt = CreateScheduledTask[writing--];
  Grid[{{ToTitleCase@StringTake[ToString@HoldForm[learning], ;; -7], 
     ProgressIndicator[Dynamic[learning], {0, maxLearning}], 
     startStop[StartScheduledTask[lt], StopScheduledTask[lt]], 
     Dynamic[learning, UpdateInterval -> 1]},
    {ToTitleCase@StringTake[ToString@HoldForm[writing], ;; -7], 
     ProgressIndicator[Dynamic[writing], {0, maxWriting}], 
     startStop[StartScheduledTask[wt], StopScheduledTask[wt]], 
     Dynamic[writing, UpdateInterval -> 1]}}, 
   Alignment -> {Left, Center}]
  ]
 ]

and you need this function:

SetAttributes[startStop,HoldAllComplete];
    startStop[startAction_,stopAction_]:=Row[{Button["\!\(\*
    StyleBox[AdjustmentBox[\"\[RightPointer]\",\nBoxBaselineShift->0.12313612313612314`,\nBoxMargins->{{0., 0.}, {-0.12313612313612314`, 0.12313612313612314`}}],\nFontSize->24]\)",startAction,Appearance->"Frameless",ImageSize->{30,30},Alignment->Center],Button["\!\(\*AdjustmentBox[\(\[FilledSquare]\),\nBoxBaselineShift->-0.1704961704961705,\nBoxMargins->{{0., 0.}, {0.1704961704961705, -0.1704961704961705}}]\)",stopAction,Appearance->"Frameless",ImageSize->{30,30},Alignment->Center]}," ",BaselinePosition->Center]