Longest Day of the Year
The Northern Hemisphere receives more daylight than any other day of the year on the summer solstice. This day marks the start of astronomical summer and the tipping point at which days start to become shorter and nights longer.
The word “solstice” comes from the Latin words “sol” (sun) and “stitium” (still or stopped). The ancients noticed that as summer progressed, the sun stopped moving northward in the sky, then begin tracking southward again as summer turned to autumn. (During the winter solstice, the sun does the opposite, and begins moving northward as winter slowly turns to spring.)
Neolithic humans may initially have started to observe the summer solstice as a marker to figure out when to plant and harvest crops. In Ancient Egypt, the summer solstice corresponded with the rise of the Nile River. Its observance may have helped to predict annual flooding.
Different cultures and religious traditions have different names for the summer solstice. In Northern Europe, it’s often referred to as Midsummer. Wiccans and other Neopagan groups call it Litha, while some Christian churches recognize the summer solstice as St. John’s Day to commemorate the birth of John the Baptist.
Solstice in Ancient Cultures
Kronia, a festival celebrating Cronus, the god of agriculture, was also held around this time. The Greeks’ strict social code was temporarily turned on its head during Kronia, with slaves participating in the merriment as equals or even being served by their masters.
In the days leading up to the summer solstice, the ancient Romans celebrated Vestalia, a religious festival in honor of Vesta, goddess of the hearth. During Vestalia, married women could enter the temple of Vesta and leave offerings to the goddess in exchange for blessings for their families.
In ancient China, the summer solstice was associated with “yin,” the feminine force. Festivities celebrated Earth, femininity, and the “yin” force.
Before Christianity, ancient Northern and Central European pagans (including Germanic, Celtic and Slavic groups) welcomed Midsummer with bonfires. It was thought that bonfires would boost the sun’s energy for the rest of the growing season and guarantee a good harvest for the fall.
Bonfires also were associated with magic. It was believed that bonfires could help banish demons and evil spirits and lead maidens to their future husbands. Magic was thought to be strongest during the summer solstice.
For more on summer Solstice: https://www.history.com/topics/history-of-summer-solstice