How to add a subtitle to the report?

[Coder2023Coder]

I want to add a subtitle to the report after the title. I am showing where I mean by a red arrow in the attached image.
I know that to change the title I should add the following to the conftest.py:

def pytest_html_report_title(report):
    report.title = "<new title>"

But with a subtitle I wonder how to add it.

Also, is it possible to modify the content of the line "Report generated on ... "?

[BeyondEvil]

Currently there's no way of adding a subtitle or altering the "Report generated..." line.

What's the use case?

The closest you can get is using the pytest_html_results_summary hook (prefix).