YOU SAID:

The day I turn twenty three I'm getting married

INTO JAPANESE

23歳になった日結婚します

BACK INTO ENGLISH

I will get married the day I turn 23

INTO JAPANESE

23歳になった日に結婚します

BACK INTO ENGLISH

I will get married on the day I turn 23

INTO JAPANESE

23歳になった日に結婚します

BACK INTO ENGLISH

I will get married on the day I turn 23