Table: rangers_fcs_1988_89
Columns: date
round
opponent
venue
result
attendance

Question: what is the date when the round is sf?
SQL: SELECT "date" FROM rangers_fcs_1988_89 WHERE "round" = 'sf'

Question: what is the date when the round is qf?
SQL: SELECT "date" FROM rangers_fcs_1988_89 WHERE "round" = 'qf'