How to write a whole site redirect rule?

You can find details here:

https://redirection.me/support/redirect-regular-expressions/

That’s fabulous … thank you very much. It took me much longer to get back to this than I’d hoped.

I have now fixed this, thanks for the help.

On https://wiki.davelevy.info/wordpress-301-redirects

I say,

I have inserted the following redirection on the target blog. ^/\d{4}/\d{2}/\d{2}/(.*) /$1/ which translates the old permalink format into the new and shorter one.

I have inserted the following rules on the old blog i.e. https://blog.davelevy,info.

^/(?!wp-admin)(.*) https://davelevy.info/$1

i.e. for everything except wp-admin, pass the URL onto the new site, I also have aa rule to pass the top level blog page onto the new blog home page since the blog is no longer the home page