I'm leaving.

I'm off.

I'm signing off for the day.

 Similar Expressions

It's quitting time.

Time to clock out.

▶ 퇴근 시간이야.

Let's call it a day.

▶ 퇴근 합시다.

Dialogue

A: Good work, everyone.  I'm leaving. 

        See everyone tomorrow. 

B: Good night, see you tomorrow!