Reb Yochanan

One may not perform several actions during the week in which Tisha B’Av falls. This is referred to as shavua she’chal bo. For example, one may not take a haircut or wash his clothing (Ashkenazi Jews are forbidden in these actions prior to the week of Tisha B’Av in accordance with the ruling of the Ramah). The Mechaber (Shulchan Aruch Orach Chaim 551: 4) writes that in a year when Tisha B’Av falls on Shabbos and is pushed off to Sunday (as it does this year) there is a machlokes as to whether there are any prohibitions during the week before Tisha B’Av. The Mechaber seemingly sides with the view that there are no halachos of shavua she’chal bo in such circumstances.