Q. Can someone who usually fasts on Erev Rosh Hashana when possible, attend a siyum and thus avoid fasting?
A. Horav Shlomo Miller’s Shlit’a opinion is that this case is similar to the Taanis Bechoros on Erev Pesach, where firstborns can avoid the traditional fast by attending a siyum.
The Rov added that although attending a siyum is a very important mitzva of joining and encouraging others that have learned and celebrating with them the successful culmination of their Torah efforts, especially on Erev Rosh Hashana, it should be done with the right and proper intentions and not just for avoiding a fast.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit’a.