CREATE TABLE table_18089 ("#" FLOAT, "Title" TEXT, "Director" TEXT, "Writer ( s ) " TEXT, "Originalairdate" TEXT, "Repeatairdate ( s ) " TEXT, "Prod.Code" TEXT)

What is the repeat date of the episode that aired 22/12/1968?
SELECT "Repeatairdate(s)" FROM table_18089 WHERE "Originalairdate" = '22/12/1968'
SELECT "Repeatairdate(s)" FROM "table_18089" WHERE "Originalairdate" = '22/12/1968'