A Sant called Harnam Singh ji Rampur Khere wale explained how and when this Gurbani is to be read. I am going to narrate the saga from his life on how he learned about this bani and its code of conduct:
Baba Ji would also do Chandi Di Vaar in his Nitnem every day. But a question arose in his mind. When should this Baani be recited and how often? He would often wonder. He asked many religious and saintly people but nobody really gave a firm answer. One day, while in the hut, he began reciting Rahiraas Sahib after which he did Chandi Di Vaar. He then finished off with Sohilaa and was preparing to go to sleep. The moon was shining outside and the door to the hut was open. He had just laid down when all of a sudden, he saw two men approaching from a distance. Baba ji thought to himself that if they are travelers then he will provide them with food and clothes and offer them a place to rest for the night. But if they are robbers, he will be prepared to confront them.
While he was still thinking they both pinned him to the ground. One held him down from the head and the other from the feet. They couldn't be travellers or robbers because they arrived at such incredible speed. They were Shaheed (martyred) Singh’s. He began doing Mool Mantar Jaap. He had just completed two Mool Mantrs when the Singh’s released him. He sat up. The Shaheed Singh’s explained to him that they didn't come to hurt him. They came to remove his doubt and confusion about the recitation of Chandi Di Vaar and when to do it, how much to do and how to do it. It was the fact that he thought that he would confront them that the wrestled him to the ground.
They explained that if Chandi Di Vaar is recited after the sunset, then it must be continued all night non-stop until day break. It is alright for two or more Singh’s to do it in turn. If an individual can recite it all night then that is alright as well. A clean cloth should be spread underneath where you're sitting and you must have your bath first. There are no strict rules about reciting in the day time. Whether it is recited one or more times, it should be done with love and affection. After saying this, they left the hut and then suddenly disappeared.
I have full faith in this sakhi, but it is up to ones own personal view. For more information on the jeevan of this Sant please visit:
http://www.sikhlionz.com/babaharnamsinghjirampurkherewale.htm
If you want the English translation or mp3 of this bani please contact me on my email which can be seen in the title section of this blog.
It is also important to note; a Sikh does not worship any Hindu gods or goddesses. A Sikh worships akal purakh (the immortal soul). This story was not written by Guru Ji; so that we can gain or ask for any power from Durga. It was written to show an example of Good vs Evil.