What is the longest day of the year called?
Quick Answer: The longest day of the year is called the Summer Solstice. It marks the day with the most daylight hours, usually around June 20th or 21st in the Northern Hemisphere.
The Summer Solstice happens because of the Earth's tilt. On this day, one hemisphere is tilted closest to the Sun, giving it the longest stretch of daylight.
After the solstice, the days slowly start getting shorter. It’s the official start of summer and has been celebrated in many cultures for thousands of years.