It’s brought down in halacha to get a haircut before Rosh Hashonah. If one is need of a haircut a week or two before YT is he supposed to hold it off, in order to get it L’kovod Yom Tov? or may he get one when needed, and not get one before YT?
Why can’t you get the haircut when you need it (it’s close enough that you will not need another) and just say “lekavod yom tov” as you sit down in the barbers chair? I think the point of it is that you elevate what you are doing, which you will be by declaring it lekavod yom tov. A woman can bake a challah on Monday (and freeze it) and still say lekavod shabbos Kodesh as she bakes. It still applies and is just as meaningful.
2/3 weeks prior to yomtov is good enough to get a hair cut lekovod yomtov. the cut will still be fresh then, plus erev yomtov there is no way you can get an appointment at an hour that will suit you… they are just all too booked out!!!