YOU SAID:
How long until disappointment?
INTO JAPANESE
がっかりするまでどれくらいかかりますか?
BACK INTO ENGLISH
How long does it take to be disappointed?
INTO JAPANESE
がっかりするのにどれくらい時間がかかりますか?
BACK INTO ENGLISH
How long does it take to be disappointed?
That didn't even make that much sense in English.