Fast of the Firstborn (,
Ta'anit B'khorot or ,
Ta'anit B'khorim); is a unique
fast day in
Judaism which usually falls on the day before
Passover (i.e. the fourteenth day of
Nisan, a month in the
Jewish calendar. Passover always begins on the fifteenth of the Hebrew month). Usually, the fast is broken at a
siyum celebration (typically made at the conclusion of the
morning services), which, according to prevailing custom, creates an atmosphere of rejoicing that overrides the requirement to continue the fast (see
Breaking the fast below). Unlike most Jewish fast days, only firstborns are required to fast on the Fast of the Firstborn.