No. I actually did mean latitude because that affects the length of the day at different times of the year. On the equator, there's not much point. Presumably, you're in a timezone that makes general sense relative to typical work patterns so that the sun is up during your awake time. Conversely, live in northern Alaska and you probably have almost too much sun in the summer so no need to optimize and it's dark enough in the winter that no fiddling with timezones is going to give you enough light.