YOU SAID:

we'd be in the same time zone

INTO JAPANESE

同じタイムゾーンにいる

BACK INTO ENGLISH

I am in the same time zone

INTO JAPANESE

私は同じ時間帯にいます

BACK INTO ENGLISH

I am at the same time.

INTO JAPANESE

私は同時にいます。

BACK INTO ENGLISH

I am at the same time.