reset date format apple mail

When I log into icloud I have noticed that the update has defaulted the date format in mail to month/ day/ year rather than day/ month/ year which as I non-American I am used to.

I can not figure out how to alter this - not been a problem before no issues on any of my Apple devices just when I log into icloud remotely.

Any solutions - old solutions on the web don't work because many of the features / buttons etc no longer exist.