As per Hindu calendar, the five day festival of Diwali is
centered on the new moon day that ends the month of Ashwin and
begins the month of Kartika, beginning on the 13th day of the dark
half of Ashwin (Ashwin 28th) and ending on the 2nd day of the
bright half of Kartika (Kartika 2nd). The main day of celebration
varies regionally.[5][6]They light diyas—cotton string wicks
inserted in small clay pots filled with oil—to signify victory of
good over the evil within an individual.While Diwali is popularly
known as the "festival of lights", the most significant spiritual
meaning is "the awareness of the inner light".
Hindus have several significant events associated with it:
The Killing of Narakasura: Celebrated as Narak Chaturdashi, one day
before Diwali day, it commemorates the killing of Narakasura, an
evil demon who created havoc, by Krishna's wife Satyabhama. This
happened in the Dwapara Yuga during this time of Krishna's
avatar
Diwali also celebrates the return of Rama, King of Ayodhya, with
his wife Sita and brother Lakshmana to Ayodhya after a 14 year
exile, and a war in which he killed Ravana. It is believed that the
people of Ayodhya lit ghee lamps along the way to light their path
in the darkness.
In Jainism, Diwali marks the attainment of nirvana by Mahavira on
15 October, 527 BC.
The festival is also celebrated by Buddhists in Nepal, a
majority-Hindu country, particularly the Newar Buddhists.
Central to Hindu philosophy is the assertion that there is
something beyond the physical body and mind which is pure,
infinite, and eternal, called the Atman. Just as we celebrate the
birth of our physical being, Diwali is the celebration of this
inner light, in particular the knowing of which outshines all
darkness (removes all obstacles and dispels all ignorance),
awakening the individual to one's true nature, not as the body, but
as the unchanging, infinite, immanent and transcendent reality.
With the realization of the Atman comes universal compassion, love,
and the awareness of the oneness of all things (higher
knowledge).