Question:
My mother passed on March 27 and burial was on March 31. When does shloshim end if Pesach begins on April 12 and is it just interrupted by Pesach or is it completely cancelled?
Answer:
Hamakom yinachem eschem b'toch shar aveilei Tzion V'Yerushalayim
The sheloshim is completely canceled. However with regard to saying kaddish, the halacha is that a person who is within sheloshim has precedence to daven for the amud, and to saying kaddish. You would still have this advantage until the first day of Iyar.