YOU SAID:

If it's night, Durden, you have to sleep

INTO JAPANESE

夜だとしたら、Durden、眠らなければ

BACK INTO ENGLISH

If it is night, Durden, if you do not sleep

INTO JAPANESE

夜であれば、Durden、眠らなければ

BACK INTO ENGLISH

If it is night, Durden, if you do not sleep