The amount of the daylight hours depends on the latitude and how the Earth orbits the sun. The orientation of the Earth’s axis to the sun is always changing throughout the year, as we revolve around the sun. Sometimes the axis points towards and other times away from the sun. As this orientation changes throughout the year, so does the distribution of sunlight on Earth’s surface at any given latitude.

People who live in the mid-latitudes, far from both the Equator and the poles, enjoy maximum daylight on the summer solstice and put up with maximum darkness on the winter solstice. Between the two extremes, sunlight increases or decreases each day, but the rate of change is not steady. The change of duration of daylight period is slowest in the June and December solstices (Solstice means “the Sun stands still”). It increases in the transition periods, and reaches its maximum halfway at the two equinoxes (when the sun is over the Equator). From its slowest of 1 minute per day in January and June it increases to 3 minutes in March and September.