And where do you live such that the sun is at the 'top of the sky' at noon?
Timezones aside (which basically average out an arbitrary time for the 1/24th of the planet you are standing in) there's the 23.5 degree axis, which means there's nowhere on the planet where the sun is at the 'top of the sky' all year.
Now, of course, there are differences between the mean solar day and the actual day, and the analemma, and all that, but to a first approximation, the sun is really closest to the top of the sky at noon, local time.
I've never heard the phrase before, and it seems to be such a wildly unpopular term that running an incognito google search on the phrase gives me three pages that contain almost exclusively references to tall buildings (Sydney, Auckland, Dubai) and some songs with a similar name.
There's one reference in that set of 30 results that refers to the astronomical term 'zenith' -- which is what I'd have naively interpreted the phrase to mean (and informs my earlier questions to GP).
In any case, as per GP's plaintive concerns over children's potential confusion in 2121, we seem to be ignoring the facts that today schools start, and shops open, at 9am, and schools & offices are open Monday to Friday, etc etc because of what some people wanted a hundred years ago -- and I'd agree that not enough people ask the obvious questions about why we're still sticking to this craziness.
But because the sun barely ever got much above the horizon, the slightest cloud cover meant it mostly felt like twilight.
I can't imagine anyone calling something 5 degrees above the horizon the 'top of the sky', but perhaps they did. I don't speak any Icelandic, so I can't really say for sure.
Interestingly the solar noon during winter (ie. not daylight savings) there is around 13:30 -- no one seemed to be terribly concerned it not being 12:00