Vivaha panchami is celebrated on the 5th waxing moon (tithi) in the month of margashira. In 2017 this falls on November 22nd in USA and November 23rd in India. It is believed that Lord Rama and Goddess Sita got married on this day!
King Janaka (father of Goddess Sita) organized a swayamvar (a ceremony where the bride chooses the bridegroom). His condition was that the brave one who can lift the bow presented to Janaka by Lord Shiva will be the one who would marry Sita. Lord Rama not only lifted the bow with ease, but he also broke it and married Goddess Sita.

Spiritual Significance
Lord Rama is the incarnation of Vishnu and he is the pure soul. Goddess Sita represents the Maya (ego) – The union of ego and soul is the ultimate purpose of life. Ego dissolves into the self. When the self is realized the ego disappears.

Astrological Significance
Lord Rama was born in the constellation of Punarvasu. The symbol of Punarvasu Nakshatra is the “bow”.