early in/on the morning of, in/ on the early morning of

[joham]

I left home early on/ in the morning of July 8th.
I left home on/ in the early morning of July 8th.
Do all these four time phrases 'early on/ in the morning of', 'on/ in the early morning of' sound fine?

Might I ask native English teachers to clarify whether these phrases can all be used.

Thank you in advance.

[Tdol]

1 on- I don't like 'in' there
2 in- but this sounds a bit stilted to me, unless something very important happened that morning