Likewise konbanwa is the same thing with "tonight" / "this evening"

English speakers also often drop the "good" in "good morning" and "good night", reducing the phrase to a single noun that refers roughly to the current time.

>English speakers also often drop the "good" in "good morning" and "good night", reducing the phrase to a single noun that refers roughly to the current time.

If I'm at work, I usually prefer to say "morning" without the "good": if it were a good morning, I wouldn't be at work...

it's short for

今日はご機嫌いかがですか？

if you're a rich girl at a private school you can just say ご機嫌よう