June 21, marks the beginning of summer season solstice, which is the longest day of the year. The day coincides with Fete de la Musique or World Music Day and International Day of Yoga. Summer solstice, also called estival solstice or mid summer, occurs when one of the Earth's poles has its maximum tilt toward the Sun. Solstice, a term derived from Latin words sol, meaning sun, and sistere, which means to stand still, is an astronomical event which occurs twice a year - in each hemisphere (Northern and Southern). The Summer Solstice is when the tilt of the earth's axis is most inclined towards or away from the sun and when the sun reaches its highest position in the sky, it's the day with the longest period of daylight. This year, the summer season begins on June 21 and ends on September 23.
The Summer season solstice falls during June solstice in the northern hemisphere. The summer solstice occurs sometime between June 20 and June 22, depending on the shift of the calendar.
The December solstice in the Southern Hemisphere occurs between December 20 and December 23. The same dates in the opposite hemisphere are referred to as the winter solstice.
The summer season solstice has been seen as a significant time of year in many cultures, and has been marked by festivals and rituals. Traditionally, the summer solstice is seen as the middle of summer and referred to as "midsummer". Today, however, in some countries and calendars it is seen as the beginning of summer.