YOU SAID:

The document date must be a valid expiry date (2018-03-04, valid for at least 3 months)

INTO JAPANESE

文書の日付が有効期限 (2018-03-04、少なくとも 3ヶ月間有効) をする必要があります。

BACK INTO ENGLISH

Date of the document should expire (2018-03-04, at least valid for 3 months).