I get it. That's pretty much where I was coming from too. Try to think of time as just an abstract intangible number that is steadily passing. We can't see time, but we can see how things change IN time.
The progression of the sun through the sky is how we see time, but time is really just the number behind that movement. Degrees of movement across the sky indicates the number of time-language moments from seconds to hours to days but is not time itself.
The hands on a clock, similarly, are not time. Just a physical representation of the numbers passing that allow us to measure time. The reason a clock works better for showing time than the sun, I'm guessing, is because the clock shows us the time in numbers whether it's a digital clock or an...would it be an analog clock? Take the numbers off a clock face and you can still see time passing, but now you're just looking at hands swinging through space unconnected to a number. Now instead of 'noon' you'd be focused on 'when both hands are pointing directly at the top of the clock, whichever way that is', which is space.
This is going to be getting theoretical again I suppose, but the way I've been thinking of it the last day or so is like Space is one extreme of a spectrum, Space-Time is in the middle, and then Time is the other extreme. Space just is. It sits where it is, unmoving, as it were. Kind of like matter. Time is a number and it flows. Kind of like energy. When we see space moving, it's Space-Time. So Timelocks have to be about a number moving and that number has to be a time number, not a space number. I think that's why CHuntley says sundown only works if you say specifically what time it is. If you don't give a time number (hour and minute) then you are giving a space number (degrees). So anythin that isn't specifically about an abstract number passing ends up being about space and options.
*take note that I've only just figured this out...or still am figuring it out...so take that with a grain of salt. The reason I'm sharing is because this is the thinking that took me from disagreeing with @MWollaeger and @chuntley to mostly being able to come to a conclusion that lines up with what they are saying.