Deepawali known as the "festival of lights". . .

Diwali  or Deepawali  popularly known as the "festival of lights".
Deepavali is popularly known as the "festival of lights", the
most significant spiritual meaning is "the awareness of the inner light".  Diwali falls on the one new moon night between mid-October and mid-November. Deepavali is celebrated for
five days according to the lunisolar Hindu Calendar. 
It begins in late Ashvin (between September and October)
and ends in early Kartika(between October and November).
Generally  occurring between mid-October and mid-November. For Hindus  Diwali is one of the most important festivals of the year.  "Deepavali" (Sanskrit: दीपावली Dīpāvalī), which translates into "row of lamps".  Diwali involves the lighting of small clay lamps (diyas or dīpas) inSanskrit: दीप) filled with oil to signify the triumph of good over evil. During Diwali, all  wear new clothes and share sweets.
The festival starts with Dhanteras, the second day of the festival, Naraka Chaturdasi and followed by
 "Amavasya", of Ashvin, is a big celebration, known as Laxmi Pujan.
 Amavasya, the third day of Deepawali, marks the worship of Lakshmi, the goddess of wealth  and Ganesh, the God of auspicious beginnings.
The word 'Dhanteras' means 'dhan' wealth and  'teras' the 13th day on which it is celebrated.
Choti Diwali or Chaturdashi is the fourteenth lunar day (thithi) of the dark fortnight of the month of Kartik and the eve of Diwali.
 In North India, the fourth  day is celebrated as Govardhan Puja, also called Annakoot, and is celebrated as the day Lord Krishna took  an incarnation of god Vishnu to defeat Indra and by the lifting Govardhana hill to save his kinsmen and cattle from rain and floods. For Annakoot, large quantities of food are decorated symbolizing the Govardhan hill lifted by Krishna.
 Bhaiduj  also Bhayyaduj, Bhaubeej or Bhayitika the 5 th day  on this day, brothers and sisters meet to express love and affection for each other . In Gujarati  Bhai Bij, Bengali Bhai Phota.  Deepavali celebrations are spread over five days, from Dhanteras to Bhaiduj.