We go away on holiday on the morning after Tisha B’Av – I would really like to have my haircut before I go away – is there any basis for doing so? Can I do it for example on Friday 20 July [2018=8 Av] for the honour of Shabbat or does that not work? What about this Friday [13 July] which is also Rosh Chodesh Av? Any chance?
I am afraid none of the options quite pass muster. Of the possibilities, this week before Friday (Rosh Chodesh) is best. There are grounds to allow shaving on Friday for the honour of Shabbat (for one who generally shaves daily), but this would not apply to a haircut (ie at a time of year when trimming the hair is restricted). I would allow a haircut/shaving during the Three Weeks for reasons of livelihood, but this is permitted in the Nine Days only in particularly extenuating circumstances. I am afraid your best option would seem to be to patronise a barber abroad on this occasion.
Rabbi Rashi Simon