Diwali is a festival that is dynamic in nature, in the sense it occurs on various days in each year. The word Diwali comes from the Sankrit word "deepavali" meaning a "garland of lamps".
During Diwali period, the luminaries Sun and Moon are in conjunction (0deg). This is a highly harmonious position in mundane astrology. They are placed in the house of Libra or Tula and Swati nakshatra rules. Libra or Tula is denoted by the balance symbol representing universal brotherhood, a much needed character for observing a festival of joy.
The ruling nakshatra during Diwali is Swati which is a feminine constellation which is linked to Goddess Saraswathi of Indian mythology ruling arts, music, learning and the like. The ruling of this nakshatra showers a happy atmosphere all through the day.
The festival of Diwali always comes on the same tithi that is Aswayuja amavasya. Astrologically, the end of this tithi- Aswayuja amavasya marks the exact conjunction of Sun and Moon in the zodiac house of Libra . It is to be noted that Libra rules business. Hence Diwali marks the start of a new financial year for most parts of North India.
During Diwali, the Sun God, Hanuman, Goddess Lakshmi and God Ganesha are worshipped fervently. It is believed that these Gods shall confer riches, health and prosperity on all during the festive period.