Why do the daylight hours change?

The Tilt of Earth's Axis

Earth's axis is tilted at an angle of approximately 23.5 degrees relative to its orbit around the sun. This tilt is what causes the changing seasons and daylight hours.

Orbit around the Sun

As Earth revolves around the sun, the angle at which sunlight reaches different parts of the Earth changes. This change in angle is what leads to longer or shorter daylight hours.

Changing Orientation

Throughout the year, as Earth orbits the sun, the orientation of its axis relative to the sun changes. Sometimes the axis points toward the sun, resulting in longer daylight hours in a particular hemisphere. Other times, the axis points away from the sun, leading to shorter daylight hours.