一昨
Noun
1
noun (common) (futsuumeishi)
one previous
一昨日
Common
Noun
Adverb
1
noun (common) (futsuumeishi)adverb (fukushi)
day before yesterday
「ウィキペディアを引用するな」という主張が昨日だか一昨日だかの朝日新聞に載っていた。
The exhortation "Don't quote Wikipedia" was included in the Asahi newspaper of yesterday or the day before.