Let's jump straight to decimal time then.

1^h^23^m^45^s^ is 1 decimal hour, 23 decimal minutes, and 45 decimal seconds, or 1.2345 decimal hours, or 123.45 decimal minutes or 12345 decimal seconds; 3 hours is 300 minutes or 30,000 seconds. This property also makes it straightforward to represent a timestamp as a fractional day, so that 2023-10-26.54321 can be interpreted as five decimal hours and 43 decimal minutes and 21 decimal seconds after the start of that day, or a fraction of 0.54321 (54.321%) through that day (which is shortly after traditional 13:00)

That's a language problem, in a lot of European languages they already work like that.

In French the way they say 9:20 a.m. is literally "the time of 9 hours 20 minutes" and 3:45 p.m. is "the time of 15 hours 45 minutes". It's written as "h1545". Which is very close to how military time works in English speaking countries.

This proposal isn't that you wake up at 7:00am Greenwich time regardless of where you are on the planet, though. The proposal is that you wake up at sunrise (or whatever), which might be at 19:00 Greenwich time, and everybody just has an absolute measure of time that's the same everywhere, abolishing timezones (potentially making it easier to schedule a meeting across timezones).

I'm not necessarily in favour of this plan, I think I'd be fine with it, but I think timezones are a somewhat useful abstraction. The one thing that always bothers me related to this, though, is the argument about whether or not we should have permanent DST or no DST based on whether we should wake up "earlier" or "later" in the sun cycle or whatever... And like... It doesn't matter. You can call it 6:00am or 7:00am, you're waking up at the same time. It doesn't matter if we call the hours that business are open from 9:00-17:00 or 8:00-16:00... When the clocks don't change the times are just arbitrary names. Ultimately I really don't care, I just want people to stop fucking with clocks every 6 months... But because the numbers are somewhat arbitrary I think we should settle on no DST because then noon more accurately corresponds to solar noon, which I think makes more sense and would help people be more in tune with the solar cycle.

Nothing in that proposal violates your objection, though.

They're not saying that people would abandon their daily schedule in favor of one that matched the schedule at GMT. Rather, the number attached to the local time would simply change to match.

It'd be utterly bizarre at first, since there'd be no understood "wake up at 6 to 8am, work through the rest of the am hours into the mid pm hours, head home at 4 or 5pm, etc ", but it seems like once you adjusted to it in your area, it would work.

For example, in my area, I'd be waking up around noon, starting work in the early afternoon, through the pm hours, finishing up around 9pm and coming home to have dinner around 11pm or 12am, and heading to bed in the early am hours. I'd still be waking up in the morning, working through the normal office hours of the day, returning home in the late afternoon, having dinner in the evening and going to bed a few hours later, at night...it's just that the numbers on the clock assigned to those times of day would be different.