The Southward equinox (or September equinox) is the moment when the sun appears to cross the celestial equator, heading southward. Due to differences between the calendar year and the tropical year, the Southward equinox can occur at any time from the 22nd to the 24th day of September. At the equinox, the sun rises directly in the east and sets directly in the west. Before the Southward equinox, the sun rises and sets more and more to the north, and afterwards, it rises and sets more and more to the south.

In the Northern Hemisphere the Southward equinox is known as the autumnal equinox. In the Southern Hemisphere it is known as the vernal or spring equinox.

Paryushana (or Paryusan) is one of the two most important festivals for the Jains, the other being Diwali. Normally Svetambara Jains refer it as Paryushana, while Digambara Jains refer it as Daslakshana. Paryushan means, literally, "abiding" or "coming together". It is also a time when the laity take on vows of study and fasting with a spiritual intensity similar to temporary monasticism.^[1][2] The duration of Paryusana is for 8 or 10 days and comes at the time when the wandering monks take up temporary residence for four months of monsoon. In popular terminology, this stay is termed chaturmasa because the rainy season is regarded to be about four months. For this minimum duration, Paryushana must be initiated by Panchami (fifth day) of the Shukla Paksha phase of the Bhadrapada month. In the scriptures it is described that Lord Mahavira used to start Paryushana on Bhadrapada pak sha panchami. After Mahavir, nearly 150 years Jain Samvatsari was shifted to Chaturthi (4th day of Bhadrapada of Shukla phase. Since 2200 years Jains follows Chaturthi.

The date for the Paryushana festival is thus Bhadrapada Shukla Chaturthi for both major sects. Because of computational and other differences, there can be some minor differences among various subsects. Recently there has been an attempt to standardize the date. Because at this time the monks have settled in the town for a longer duration, it is time for the householders to have an annual renewal of the faith by listening to the statement of the Dharma and by meditation and vratas (self-control). In the Digambaras, it is done by starting a 10-day period from Paryushana (Bhadrapada Shukla panchami) during which the dashalakshana vrata is undertaken. In the Shvetambaras an 8-day festival is celebrated that ends with Bhadrapada Shukla chaturthi. The last day is called Samvatsari, short for Samvatsari Pratikramana.

Ganesh Chaturthi (Marathi: गणेश चतुर्थी, Konkani: चवथ, Hindi: गणेश चतुर्थी, Malayalam: വിനായക ചതുര്‍ത്ഥി, Tamil: விநாயகர் சதுர்த்தி, Kannada: ಗಣೇಶ ಚತುರ್ಥೀ, Telugu: వినాయక చవితి), also known as Vinayaka Chaturthi, is the Hindu festival of Ganesha also called Vinayagar in Tamil Nadu, the son of Shiva and Parvati, who is believed to bestow his presence on earth for all his devotees in the duration of this festival. It is the day Shiva declared his son Ganesha as superior to all the gods. Ganesha is widely worshipped as the god of wisdom, prosperity and good fortune and traditionally invoked at the beginning of any new venture or at the start of travel.

The festival, also known as Ganeshotsav ("festival of Ganesha") is observed in the Hindu calendar month of Bhaadrapada, starting on the shukla chaturthi (fourth day of the waxing moon period). The date usually falls between 19 August and 15 September. The festival lasts for 10 days, ending on Anant Chaturdashi (fourteenth day of the waxing moon period).