I agree with your concern. I think dinner should be served up to 8pm. I also think breakfast should stop after 9am. A 9:45am (say IAH-LAS) is too late to serve breakfast. I have tried and can not get CO to change.

If you fly DL - they serve lunch on a flght after 9 - so if you go ATL-LAX at say 9:10am - you will get lunch. Not sure what DL's cut off is for dinner.