YOU SAID:
Mia is going to be here today.
INTO JAPANESE
ミアは今日ここに来る予定です。
BACK INTO ENGLISH
Mia is scheduled to be here today.
INTO JAPANESE
ミアは今日ここに来る予定です。
BACK INTO ENGLISH
Mia is scheduled to be here today.
That didn't even make that much sense in English.