Should Diwali be celebrated on the night of the New Moon or on Amavasya?

Dear Editor,

Just one minute, please. Is Diwali celebrated on the night of the New Moon, or on Amavasya? There is a significant difference here. I understand them to represent different phases of the moon. Amavasya is the 15th and last lunar day of the dark fortnight, while the New Moon which is called ‘Chandra Darshan’ (appearance of the moon), is the first phase of the bright fortnight. That is why it is called ‘new’ since it marks the beginning of a new phase. The 10th is Amavasya. The birth of the new phase begins at 13:47 on the 11th. However, the crescent is not visible because of its close proximity to the sun, but it is there. It becomes visible from the second or third night in the west.

You decide.

Yours faithfully,
Pt R Balbadar