Next week, on June 21, the United Arab Emirates will experience its longest day of the year. It’s called The summer solstice, an astronomical event that occurs once a year and signifies the start of summer in the Northern Hemisphere.

The dates of the solstices vary as they rely on when the sun crosses the celestial equator’s northernmost point. Generally, it alternates between June 20, 21, and 22, but it falls on June 21 this year.

What exactly is the summer solstice?

The summer solstice is the day of the year when the Northern Hemisphere—the portion of the planet that is north of the equator—receives the most sunshine. In terms of astronomy, this is the time when the sun is moving along its northernmost arc in the sky. As this particular day is the longest of the year, the night that follows will also be the shortest.