Like others have said, mostly based off of experience and reference.<p>For example, I&#x27;ve baked a pizza enough times _with_ a timer and specific, but different temperatures set that now I need neither and can just adjust the temperature to what I&#x27;m used to and know that the pizza only needs a certain amount of time. The end result should be a certain way. As long as it gets there correctly then whether there&#x27;s a timer&#x2F;no timer it should be fine.