If "Habari ya/za leo?" is translated "How is the day?", then why can't "Habari za asubuhi, baba?" be translated, "How are (you) this morning, father/dad?", as well as "Good morning, father."? The answer is "Nzuri.", which is nonsense in answer to "Good morning"!
How are you this ____, grandfather?" was accepted as an alternative translation for a sentence like this one. I think "How are you, this morning, Father?" should be accepted as an alternative translation for this one, too.