Sastras advice to fast on Maha Siva Ratri (the yearly most important of all “Siva nights”).
Certainly one can derive great benefit in worshipping Lord Siva as the greatest of all Vaisnava (vaishnavanam yatha sambhuh) and especially on this day.
However Vrajavasis did not give as much importance to Siva Ratri as the Saivas do.
(see Krishna Book, Chapter 34)
So who wants to fast and chant more on Maha Siva Ratri is encouraged to do slo, but Gaudiya Vaisnava in the line of Srila Prabhupada are not obliged.
- Manonatha Dasa (ACBSP)