YOU SAID:

i have a week left on the planet

INTO JAPANESE

私は地球上に1週間残っている

BACK INTO ENGLISH

I have been on earth for a week.

INTO JAPANESE

私は1週間地上にいました。

BACK INTO ENGLISH

I was on the ground for a week.

INTO JAPANESE

私は1週間地面にいました。

BACK INTO ENGLISH

I was on the ground for a week.