Row of lamps
From Sanskrit 'dipa' (lamp) + 'avali' (row). Also written Deepavali.
The five-day festival of lights around the new moon of Kartika, when lamps are lit and Lakshmi is worshipped.
What an aarti is, how it is sung at the end of puja, and eighteen aartis arranged by the deity each is sung to, with the best known linked in the story.
What a chalisa is, the verse forms it uses, and twelve chalisas arranged by the deity each one praises, with every hymn linked where the story names it.
The four-day festival of gratitude to Surya, the Sun God, observed with rigorous fasting and river-bank worship across Bihar, Jharkhand, Uttar Pradesh, and Nepal.
Diwali is a five-day season at the Kartika new moon (October-November). This sets out the days, the Padma Purana and al-Biruni, and which stories are later.
Kartik Purnima is the sacred full moon of the Hindu month of Kartik, celebrated as Dev Deepavali, Tripura Purnima, Guru Nanak Jayanti, and the close of Chaturmas, with river bathing and lamp offering.
After his father's execution, Guru Hargobind wore two swords, Miri and Piri, at the new Akal Takht, uniting temporal and spiritual authority in one Guru.