YOU SAID:
today is going to be a good day
INTO JAPANESE
今日は良い一日になるだろう
BACK INTO ENGLISH
Today will be a good day.
INTO JAPANESE
今日は良い一日になります。
BACK INTO ENGLISH
Today is a good day.
INTO JAPANESE
今日はいい日です。
BACK INTO ENGLISH
Is a good day today.
INTO JAPANESE
良い日は今日です。
BACK INTO ENGLISH
Good day is today.
INTO JAPANESE
良い日は今日です。
BACK INTO ENGLISH
Good day is today.
That didn't even make that much sense in English.