The Chaturthi, which falls on Tuesday, is called Angaraki. Angaraki means the planet Mangal (Mars) or the earth (bhumi). Ganapati is the presiding deity of Mangal just as He is of the earth. Ganapati and Mangal both have the same complexion. On the day of angaraki Ganesh frequencies reach the earth in greater quantities. The Ganesh frequencies from Mangal too reach the earth.
Consequently most of the frequencies coming from the moon are destroyed. Hence the benefit obtained by performing ‘angarika vinayaki’ and ‘angarika sankashti’ is equivalent to a series of vinayakis and sankashtis performed in a year.
Angaraki is not a vowed religious observance like others performed throughout the day and night. It is an observance composed of five prahars (one prahar is a period of about three hours), four during the day and one at night.
According to the ritual, a meal should be taken at moonrise. Thus that meal becomes a part of the ritual and is not partaken of to end the fast.