on the morning of April 4

[dido4]

Who were with you on the afternoon of May 9?

Q1:Why the preposition is not in? We say in the afetrnoon, don't we? Can we use in in the sentence?

Q2:What's the difference?

I got the sentence from an English textbook. And also the following sentence:They were home on the evening of Aug. 7.


Thank you

[Bridget]

They're correct. The "on" looks at time as a point, and not a period, where you might see "in".