In our home the day between Diwali and the New Year was always Kali Chaudas, it is only when I grew up and mingled with other community friends that I discovered that many of them referred to the day in between as Chotti Diwali which was spent in preparation for the big day. When I became part of the media and had to often do culture stories I gathered that this was a big day for the Bengalis as it was the day they prayed all night to worship Goddess Kaali. It is the longest and the most difficult puja of the festival.
In the past, these pujas were only conducted at home but over the years communities get together and celebrate it together at pandals.
My strongest memory of Kali Chaudas is mother walking down with a pot filled with water, she looked for crossroads and on finding one she stood in the centre then slowly going round spilled the water from the pot all around her.
It is said that our ancestors followed this custom to discard all the negative vibrations from the house.