Tu B'Av, or the 15th of Av, is considered a minor Jewish holiday and is known as the "Day of Love" or Kabbalistic Valentine's Day. In ancient times, the 15th of Av marked the start of the annual grape harvest. To commemorate the day, the daughters of Israel would dress in borrowed, white clothes and dance in the vineyards. The Talmud shares that there is no holy days as happy as Tu B'Av (and Yom Kippur). Clothing was borrowed on this day in order to show respect for the poor and to ensure that everyone was properly clothed, a hint towards the unity of the day.
According to the Talmud, while the Israelites were wandering in the desert for 40 years, the daughters of Israel were not permitted to marry outside of their tribes. This restriction was likely put in place to prevent inherited territory from passing to other tribes. This ban on inter-marriage was lifted on the 15th of Av and many associate this historical event with the modern day reason behind connecting to weddings, romance, and a renewal of vows on the day.
The holiday is also considered a counter-balance and high point to the month of Av, following the low energy associated with the three-week and nine-day period culminating on the 9th of Av, Tisha B'av, a day or mourning. For this reason it is also a good time to rejoice on Tu B'Av.
Like all holidays, there is a deeper, mystical aspect to the day. On the 15th of every month in the Jewish, lunar calendar, we experience a full moon. Tu B'Av, the 15th of Av, is likewise a full moon and we have the opportunity to experience the connection between the upper and lower realms. Specifically, the moon has no Light of its own and is considered, Malchut, representing the physical realm. When there is a full moon, the Light of the sun, representing the upper realms (Zeir Anpin) is fully reflected on the moon and in essence connects the physical with the spiritual. When this takes place each month we can connect to this energy and it is a great time for new beginnings - whether marriages or business ventures.
On Tu B'av however, we have an even greater connection to positive beginnings and romance as the astrological sign of Av (Leo) is ruled by the sun and we experience the highest connection between the sun (Zeir Anpin) and moon (Malchut). The Talmud and the great Kabbalist, the Ari, further share that Tu B'Av is a great day to find your soulmate due to the holy energy of the day. They share that a man who marries for the sake of heaven and to help contribute to a global correction or tikkun, versus marrying for money, beauty or fame (desire to receive for the self alone), will experience the same erasure of sins as experienced on Yom Kippur.
If the discussion about connecting Zeir Anpin and Malchut on Tu B'av is hard to conceptualize, do not to worry. Unlike most other holidays, there is no specific observance or restriction required to connect to and manifest the Light of the Creator on Tu B'av.
Simply by understanding about the holiday and the energy of love that is available for all of humanity on that day, you will have a powerful Tu B'av connection.
Use the day to get married, renew your vows, propose, start a new venture or otherwise connect to a new and positive beginning.
Happy Tu B'Av - enjoy!