Changing the clocks: Latitudes and attitudes

Next month, many countries, including the US, will adjust their clocks by one hour, a practice that is being challenged by people on both sides of the Atlantic. Opponents argue that clock changing is harmful, but they fail to consider the discomforts that would arise at certain latitudes without this practice. Human physiology suggests that the start of the day should be linked to sunrise, and at low latitudes where sunrise times do not vary much, clock changing is unnecessary. However, at midlatitudes, such as NY City, where sunrise times oscillate by three hours over the course of the year, it is difficult to find a start time that works for both seasons without changing the clocks. Clock changing helps people accommodate the extreme sunrise times in winter and summer, and can be seen as a compromise.