Student or Learner
Hi Sir! How're you doing? I'm a beginner in the field of English. That's the reason why I'm writing it to you. My question to you is:
Are the sentences as put below correct?
1. I shall have taken exercise by that time.
2. I shall have taken exercise at 2:00 pm.
3. I shall have taken exercise by the night.
Summary of the question is that I just want to know the use of 'by and at' in Future Perfect.
Please, help me if I'm wrong.