See question 3780 regarding fasting on Erev Shabbos Parshas Chukas. If one follows the vast majority of people who are not even aware of this particular mournful and tragic anniversary of the burning of so many Sefarim and original unique texts, and does not fast the whole day until Shabbos begins, should he at least fast a few hours in the morning if possible?

Horav Shlomo Miller’s shlit’a opinion is that it is commendable and propitious to do so. (Specifying that it is done ‘Beli Neder’)