Q. Do a bride and groom to be married on the eve of Assara Beteves have to fast during the day before the chupa, on the ninth of teves also?
A. The chosson and kalla have to fast during the seven days of sheva brochos after their wedding, on all days of taanis tzibur including Assara Beteves. (Mishna Berura 559: 35 and others).
However, if they find it is to hard for them to fast two consecutive days, Horav Shlomo Miller’s Shlit’a opinion is that the may fast on the ninth of teves only a half a day until chatzos until they daven Mincha. (See also Aruch Hashulchan E.H. 61: 21).
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit’a.