Business hours is no more or less of a social construct than DST or the 24 hour clock.
The only difference is that we have a shot at making everyone agree on a timezone shift or permanent DST, but absolutely NO SHOT at getting every business to switch to an 8-4 schedule. None. It’d be a nice sentiment. But it’s not happening, and I don’t care what the number says on the clock when I leave work as long as it’s sunny outside.
Why is it so important that the sun reaches its zenith at noon anyway? Do you often get confused while looking at your antique sundial?