YOU SAID:
hello how was your day
INTO JAPANESE
こんにちは今日はどうだった
BACK INTO ENGLISH
Hi today I was?
INTO JAPANESE
こんにちは本日は?
BACK INTO ENGLISH
Hi today?
INTO JAPANESE
こんにちは今日ですか?
BACK INTO ENGLISH
Hi today?
That didn't even make that much sense in English.