[Grammar] "Sunday morning" or "on Sunday morning"

[lagoo]

I came across a sentence which is "A federal appeals court early Sunday morning denied the US government's emergency request to resume President Donald Trump's travel ban."
can I say" A federal appeals court early on Sunday morning ......."


or both expressions are ok?

 

[teechar]

can I say" A federal appeals court early on Sunday morning, etc?"
Are both expressions are OK?

That's a good question. Yes, it's possible, but the reason sometimes "on" is omitted in such sentences is because of the potential confusion with "early on."
So, if you remove "early", "on" would work and there wouldn't be any potential issues.

https://www.merriam-webster.com/dictionary/early on