The June Solstice 2017 is only a few days away, marking the beginning of summer.

The first day of beach season kicks off Tuesday, June 20 in the Northeastern Hemisphere, known as the June solstice. The date is determined by astronomical phenomena–solstices happen when the sun’s zenith is at its farthest point from the equator.

In the summer solstice, it happens during the northernmost point and the North Pole facing directly towards the sun at roughly 23.4 degrees. It occurs when the sun is directly over the Tropic of Cancer in the Northern Hemisphere.

There are two solstices every year: in December and in June. The June one happens first (naturally), marking the beginning of summer, while the winter solstice takes place when the Sun is directly over the Tropic of Capricorn, marking the beginning of winter.

There’s a number of ways in which the summer solstice is celebrated throughout the world. Perhaps the most popular one is the Stonehenge structure, consisting of massive stones that bring about the beginning of summer with their positioning within the planet.

Because of the way the two hemispheres are affected by the movement of the Earth in relation to the sun, the June solstice marks the beginning of winter for those in the Southern hemisphere, while the winter solstice for us marks the beginning of summer for those below the equator.