The summer solstice is the longest day of the year, marking the official start of summer. It occurs when the Earth's tilt toward the sun is at its maximum, resulting in the most daylight hours. This event typically falls around June 21 in the Northern Hemisphere and December 21 in the Southern Hemisphere. Many cultures celebrate the solstice with festivals, rituals, and gatherings to honor the sun's energy and the season's abundance. It's a time to embrace the warmth, growth, and vitality that summer brings.