Ты занята завтра после полудня?

English Translation

Are you busy tomorrow afternoon?

Pronunciation:

полудня → полу́дня

Apparently, the stress mark generator skipped over полудня. This tends to happen when a word with a single spelling can be accented in multiple places, but that’s not true here.

I understand that the automatic stress mark generator is imperfect, but a human should be checking for missing accent marks. That apparently didn’t happen.