The last 5 days of the month of Karttika are traditionally known as
the Bhishma Panchaka or the Vishnu Panchaka. In the Hari Bhakti
Vilasa, it is said that if one is capable, one should observe
fasting from certain foodstuffs on the Bhishma-panchaka for the
pleasure of the Lord. This is optional. The Padma Purana say that
one pleases the Lord and makes spiritual advancement by such
austerities.
