Common agreement about the day's layout or schedule confers so many advantages that a standard DST schedule has generally been chosen over ad hoc efforts to get up earlier. The advantages of coordination are so great that many people ignore whether DST is in effect by altering their nominal work schedules to coordinate with television broadcasts or daylight. DST is commonly not observed during most of winter, because its mornings are darker; workers may have no sunlit leisure time, and children may need to leave for school in the dark. Since DST is applied to many varying communities, its effects may be very different depending on their culture, light levels, geography, and climate; that is why it is hard to make generalized conclusions about the absolute effects of the practice. Some areas may adopt DST simply as a matter of coordination with others rather than for any direct benefits.