from what i can see in the owners manual the timer should have no bearing on the cooking process but you would have to find this out
if you remove the top of the oven and look behind the thermostat knob
if its got a small capilliary tube coming off it that goes into the oven then its likley the clock is only there to tell the time and control the over if your out
if so the clock may be able to be bypassed and disconnected so the unit works without it
i would need some pic to confirm this of the back of the controls and any other control boards