Bhadrapada Masam has acquired unique significance and prominence in Hindu religion. It is the sixth month in the Hindu Lunar calendar starting from Chaitra Masam. It occurs exactly half way through the Lunar year. This coincides with the rainy season (Varsha Ruthu) that generally occurs during August-September as per English calendar. A lunar month is denoted by the name of the constellation the Moon is on the full Moon day. When the Moon is in the constellation of Poorvabhadra on the full Moon day that month is denoted as Bhadrapada Masam. Bhadrakaram Bhaadrapadam. That means the month Bhadrapada is an auspicious month that is also highly meritorious. Bhadra is a Sanskrit word that also means safety.
Starting from Swarna Gouri Vratha and Sri Vinayaka Chaturthi, number of Divine festivals occurs during Bhadrapada Masam. Second day after Sri Ganesha Chaturthi known as Rishi Panchami is earmarked for worshipping of Sages (Saptha Rishis) exclusively meant to be observed by women. 6th day in the lunar month Bhadrapada Masam (Shasti thithi) is known as Surya Shashti. It is highly meritorious to take bath early in the morning on this day, worship the Sun God and take Panchagavya (a mix of five items related to the sacred Cow). This is supposed to give merits equivalent to Ashwamedha. Eighth day (Ashtami) thithi is meant for Jyesta Devi Pooja that is generally performed for three days by the married women.
Bhadrapada Sukla Ekadasi known as Parivarthini Ekadasi is the day Lord Sri Maha Vishnu turns his position while in Yoga Nidra. This day is a turning point in the Chaturmasa Vratha. The day on which Lord Vamana was born (Sri Vaamana Avathara) is celebrated every year on Bhadrapada Sukla Dwadasi as Vaamana Jayanthi. On this day Lord Sri Maha Vishnu is worshipped and Arghya is given to Lord Sri Vamana. 14th day Sukla Chaturdasi is known as Anantha Chaturdasi when Lord Sri Maha Vishnu is worshipped in the form Anantha by observing a unique vratha known as Sri Anantha Padmanabha Vratha. Lord Sri Krishna is said to have explained the significance and merits of performing this vratha to Dharmaraja. Lord Sri Maha Vishnu in the name of Hrishikesha is the presiding Deity (masa niyamaka) for Bhadrapada Masam. Hrishikesha (Hrishika + Isha) means Lord of the senses.
If there is a coincidence of Bhadrapada Masam, Krishna Paksha (dark fortnight), Sun in Hastha constellation and Moon in Rohini constellation, Shashti thithi, Sunday and Vyatheepatha Yoga, that day is known as Kapila Shashti. Any charity, worship, homa, sacred bath etc... performed on this day is said to be highly meritorious.
While the first half of the month is dedicated to the worship of Devathas and Rishi Gana, second half of Bhadrapada Masam is totally dedicated to the worship of Pithru Devathas that is known as Pithru Paksha or Mahalaya Paksha. During this fortnight we pay our obeisance to our forefathers by performing sacred rites. During this month giving Paayasa (Kheer), Jaggery, Anna, Lavana (Salt) as charity is highly meritorious.
Such is the significance of Bhadrapada Masam that it is auspicious for worshiping a blend of Deities, Sages and Pithrus; a unique opportunity to get discharged from Deva, Rishi and Pithru rina.