Summer Solstice

The Summer Solstice is a event in Animal Crossing: New leaf where the sun stays up the whole day. The summer solstice happens at around June 20th-22nd. The event also happens in real life as well. In new leaf, there is a little celebration. During the Solstice, the first time the player goes to the plaza and talks to Isabelle, The player will recieve Ladder Shades. The villagers may overreact to it.

Real Life Definition
The summer solstice occurs when the tilt of a planet's semi-axis, in either the northern or the southern hemisphere, is most inclined toward the star (sun) that it orbits. Earth's maximum axial tilt toward the sun is 23° 26'. This happens twice each year, at which times the sun reaches its highest position in the sky as seen from the north or the south pole.

Refrences
http://en.wikipedia.org/wiki/Summer_solstice