Deepawali in north India is celebrated as the day when Sriramchandra returned to his capital Ayodhya and the whole city decked up in lights; he was welcomed with sweets and crackers were burst in joy. That tradition continues.
Sriramchandra was the elder-most son of King of Ayodhya, Dasharatha, but his stepmother Kaikeyee procured a boon from her husband and made her own son the king and Sriramchandra was exiled with the condition to live like a sage in forest for 14 years. His wife and doting brother Laxman followed him. During his stay in forest he insulted Demon King Ravana’s sister, he in turn kidnapped Sita. Ram rescued her after long war and death of Ravana, he returned to Ayodhya on Deepawali with Sita and Laxman.
In my province Bengal its Kalipuja, the puja of Warrior Goddess Makali- but at present they have adapted the north Indian style of deepawali- crackers, sweets, lights- the only difference is north Indians worship malakshmi on this day and Bengalis worship Makali.
The puja starts at mid-night and continues almost up-to dawn.