I don't believe FitDay does those calculations, but there is an activity listing for Walking uphill, 3.5 mph.
Does your treadmill calculate calories burned for you? If so, and if you believe it's accurate, you can tweak one of the existing activities to make it close to the calorie burn. Those machines are limited in terms of accuracy, though, so YMMV.
And now that you don't have to be perfect, you can be good.