FASTING FROM ALL GRAINS AND BEANS AND BREAKING FAST ON THE NEXT DAY.

The Agama Sastra states, VAISNAVAIR NA TU KARTAVYA SMARAVIDDHA CHATURSADI, Vaisnavas should not observe Nrsimha Chaturdasi fast on that day if that day is combined with the previous day (i.e. mixed with
trayodasi). Vaisnavas should observe only the pure and unmixed chaturdasi fast.

  tava kara-kamala-vare nakham adbhuta-sringam
dalita-hiranyakasipu-tanu-bhringam
kesava dhrita-narahari-rupa jaya jagadisa hare

O Lord Kesava, O Lord of the Universe, O remover of miseries of Your devotees, all glories to You. You had adopted a form of half-lion and half man and killed the beelike demon Hiranyakasipu by using the spectacular nails on Your lotus hands. This act is so surprising because the bee usually tears at the heart of a lotus, whereas in this instance You ripped the bee like Hiranyakasipu with Your lotus petal-like hands.