Sunsets vary throughout the course of the year. One way in which they differ throughout the year is by time. The reason that the time of the sunset varies each day is due to the tilt of the Earth's axis in combination with movement around the orbit. The earliest sunset takes place at the winter solstice on December 21st. This is because the Earth is tilted back on its axis, making the Northern hemispere farther away than the Southern Hemisphere and not allowing the light to reach its surface for as long. The latest sunset takes place at the summer solstice on June 21st. This is because during this time the tilt of the Earth's axis makes the Northern hemisphere lean closer into the sun and allows for more time for sunlight to reach the Earth.

For one or two weeks surrounding both solstices, sunrise and sunset get slightly later each day. Even on the equator, sunrise and sunset shift several minutes back and forth through the year.

For sunset times in your area use the sunset calculators located on the index.