AZ and Hawaii experience ranges of [10-14 hours] and [11-13.5 hours] of daylight across the whole year, respectively. More southern latitudes can get away with not shifting their clocks because the daylight variance is much smaller. In AZ, sunrise varies from 5:15AM to 7:25AM. In Seattle, without DST, it would range from 4:11AM to 7:57AM. If we use "civil twilight" (bright enough for outdoor activities), Seattle would start experiencing daylight at 3:30AM in mid-summer.