Can we do hair cut before sunset on this Friday if my sister kevura in Israel will be at 10 AM today Sunday in NY time other wise will be till lag vaomer
H’makom yinachem eschem b’toch shar aveilei tzion v’yerushalayim.
An avel for a sister is not allowed to take a haircut until the shloshim, therefore even though the shiva will be finished when the yom tov comes in, you would still not be allowed to take a haircut then. However you don’t have to sit on a low chair, and you may put your shoes on from after chatzos, even though normally it would only be permitted later, but since erev pesach after chatzos is considered a yom tov, therefore these things are permitted.
M:B 548-27, Chochmas Admo 169-3, Pnei Baruch 27-5.