Say when you are going to do something.

Example: Have you cleaned the car? (tomorrow)

Not yet I'm going to clean it tomorrow...

Have you called Tom? (after lunch)

Not yet. I'm going to call him after lunch

Have you had dinner? (in a little while)

Not yet I'm going to have it in a little while

Have you painted your apartment? (soon)

Not yet I'm going to paint it soon

Have you fixed my bicycle? (this afternoon)

Not yet I'm going to fix it this afternoon