My mother was buried on June 19 , 2018 in morning in USA. When is shloshim?
Hamakom yinachem eschem b’toch shar aveilei tzion v’yerushalayim.
The shloshim is calculated as the thirtieth day after the burial. Therefore the shloshim will be on the 6th of av, July 18th.
Y:D 395-1, Taz Y:D 402-6, Shach ibid 5.