Thanks for the question.
If left alone will it eventually finish the cycle.
No not until it is manually moved
If thats the case then yes replace the timer, its cheaper to buy the timer at Sears , the part number is(NNN) NNN-NNNNthe cost $ 117.73.
4 screws holding the trim and timer mechanism.There is 1 Phillips screw holding the timer to remove,and a plastic piece to pull out from the back of the timer.I easily pulled it off,and the timer fell right off.I removed the wiring harness,and removal was done.Installing the timer was a reversal of the process.Slide the timer in place.install 1 screw,snap wiring harness on.push timer dial on,shroud back in place and 4 screws to put back in