Hi,
'Clive told me he had an interview'.
In the above sentence, the first past action is 'had an interview' and the recent action is 'Clive told me'.So, I conclude the interview was before Clive told me. No. Maybe it's the first example below, in blue, where the interview comes after the telling.
Let's change the guy from'Clive' to 'Tom', it confuses me to be part of the action! Different example, different colour.
Tom says to Mary, 'I have an interview', meaning it is later.
Mary may report this as 'Tom said he had an interview'.
Tom says 'I had an interview', meaning it was in the past.
Mary may report this, again, as 'Tom said he had an interview'.
Tom says 'I have had an interview', meaning it was in the past.
Mary may report this as 'Tom said he had an interview'.
The reported speech in examples 2 and 3 can be misinterpreted, and confused with the meaning in example 1. To avoid this, Mary can and should use the Past Perfect in her reported speech in examples 2 and 3.
I hope this helps. If not, please write again.
Clive