There are too many variables to give a direct answer.
My best guess/estimate would be from 12-25 minutes at 350f-375f.
Start checking after 12 minutes to see if a toothpick comes out clean or the cake is firm to the touch, continue to check every five minutes until you are satisfied.
In the instances you cited, the thickness of the cake is more critical to baking time than length and width. As Got Garlic said, only about 12 minutes.