YOU SAID:

This is going to the best day of my life

INTO JAPANESE

これは私の人生で最高の日を迎えることになる

BACK INTO ENGLISH

This is going to be the best day of my life

INTO JAPANESE

今日は人生で最高の日になるだろう

BACK INTO ENGLISH

today will be the best day of my life

INTO JAPANESE

今日は私の人生で最高の日になるでしょう

BACK INTO ENGLISH

today will be the best day of my life