This is my first question on this website!
I want to say something like "The meeting will be held at 9:30 in the morning of Sep 12, 2019." and "I will be on a travelling business in Sep 30, 2019."
How to naturally use the time expressions “at 9:30 in the morning of Sep 12, 2019” and "in Sep 30, 2019" in daily conversation?
Welcome! The only issue I see in your phrasing is the preposition choices. Some of the choices are not technically wrong but are not natural use to this American at least.
“The meeting will be held at 30 in the morning on September 12, 2019.”
Note: you can say “on the morning of September 12,” but usually when a time is included, we say “on” because “in the morning” goes with the time. When there is no time, it becomes “on the morning of...”
“I will be travelling on business on September 30, 2019.”
