Q. Can a pruzbul be done at night?

A. Ohr Sameach (Shmittah 9: 18) debates whether a pruzbul can be processed at night. Maharikash (C. M. 67: 31,) Tzitz Eliezer (6: 39,) and others permit, since it is not basically a court act. However, Shvus Yitzchok (p. 59) quotes Horav Eliashiv zt”l that on the onset, it should be written during the day. (Horav M. M. Lowy Shlit”a published locally that it can be done at night)
Horav Shlomo Miller’s opinion is that in need it can be done at night.

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit”a