The Vedic Maths does not compute...

Ok, this is really funny.

In the Hindu lunar calender calendar, dates are reckoned by fortnight. So the 16th day of the month will be called Krushna paksha pratipada* (first day of the fortnight of the waning moon). Hindu festivals often have the name of the day they fall on within their name (eg the Ganesh festival falls on the fourth day of the fortnight, hence Ganesh Chaturthi).

Now in the four days of Diwali, their are four major tithis, Dhana Trayodashi (thiteenth day), Narak Chaturdashi (fourteenth day), Amavasya (New Moon) and Bali Pratipada (first day of the new month).

However, this year, Dhana Trayodashi is on the 30th of October. But Narak Chaturdashi is on the 1st of November. Also, Amavasya and Bali Pratipada are on the same day, the 2nd of November. It seems impossible to me that there can be a day's gap between the 13th and 14th days of the fortnight, or that the last day of one month and the first day of the next month fall on the same day.

So am I missing something here, or are the tithis in Diwali reckoned differently?

(*By my Marathi Kalnirnay calender calendar. The names might be different in other languages, I don't know.)