How to express the morning of May 5th in English? How many ways are there?

1) In the morning, it usually means a long time in the morning, and on the morning means the exact morning. For example:

I often exercise in the morning.

I was born in the morning of1March, 9781ST.

2) The difference between the morning of May 1 day and the morning of May 1 day:

It means "the morning of May 1st"

The morning of May 1 day is a pure time from small to large.

"of May 1" is used as a postattribute in on the morning of May 1 to modify morning.