YOU SAID:

Its having an operation on Sunday the 54th of August.

INTO JAPANESE

8月54日日曜日に手術があります。

BACK INTO ENGLISH

I have surgery on Sunday, August 54th.

INTO JAPANESE

8月54日日曜日に手術を受けます。

BACK INTO ENGLISH

I will have surgery on Sunday, August 54th.

INTO JAPANESE

8月54日日曜日に手術をします。

BACK INTO ENGLISH

I will have surgery on Sunday, August 54th.