YOU SAID:

i am leaving for Beijing next month

INTO JAPANESE

私は来月北京へ出発します

BACK INTO ENGLISH

I will leave for Beijing next month

INTO JAPANESE

私は来月北京へ出発する予定です

BACK INTO ENGLISH

I am leaving for Beijing next month.

INTO JAPANESE

私は来月、北京に出発します。

BACK INTO ENGLISH

I am leaving for Beijing next month.